Supporting Information File 1
for
A highly efficient green synthesis of 1, 8-dioxo-octahydroxanthenes
A. Ilangovan,a,* S. Malayappasamy,a S. Muralidharana and S. Maruthamuthub
aSchool
b
of Chemistry, Bharathidasan University, Tiruchirappalli – 620024, India
Corrosion Protection Division, Central Electro Chemical Research Institute, Karaikudi-630 006, India
*Corresponding author. Tel.: +91 9865436093; Fax: 04312407045 E-mail Address: ilangovana@yahoo.co.uk
Experimental procedures and characterization data
Content
Page
General experimental conditions
General procedure A: Preparation of 2,2'-(arylmethylene)bis(3hydroxy-5,5- dimethyl-2-cyclohexene-1-one)
S2
General procedure B: Preparation of 3,3,6,6-Tetramethyl-9-aryl3,4,5,6,7,9-hexahydro-2H-xanthene-1,8-dione
S1
S9
GENERAL EXPERIMENTAL CONDITIONS
All the commercial reagents and solvents were used without further purification
unless otherwise stated. Melting points were recorded on GUNA 478 melting point apparatus
and are uncorrected. All yields reported are based on isolated compounds. TLC separations
were carried out on silica gel plates with UV indicator from Aldrich; visualization was by UV
fluorescence or by staining with iodine vapor. NMR spectra were recorded on FT-NMR
Bruker 400MHz spectrometer as CDCl3 / DMSO solutions with TMS as internal reference.
For compounds already known in the literature Melting Point and 1H NMR values are
given and compared with the spectral data already known and suitable references are also
mentioned.
General Procedure A:
1. General Procedure for the Preparation of (3)
To a solution of an aldehyde (1 mole) and 5,5-dimethyl-1,3-cyclohexanedione (2 mole)
SmCl3 was added and stirred at ambient temperature till the reaction was complete. The
progress of the reaction was monitored by TLC (Silica gel, 9:1 Hexane:EtOAc). After
completion of the reaction), filtered and dried to the product. The spectral data of 2,2’arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) derivatives 3a-3o are given
below.
1.1. 2,2'-(phenylmethylene)bis(3-hydroxy-5,5- dimethyl-2-cyclohexene-1-one) (3a):
The reaction was carried out according to the general experimental procedure using
benzaldehyde (100 mg, 0.0009 mole), 5,5-dimethyl-1,3-cyclohexanedione (241 mg, 0.0018
mole) and SmCl3 (24.2 mg, 10 mol%) in water (1 mL) Conditions: room temperature, 20
minutes. The title compound 3a was obtained (341 mg, 97%) as a solid. The spectral data for
the compound 3a was in agreement with the values already reported in the literature [1].
S2
Mp: 186-188 0C. 1H NMR (400 MHz, CDCl3):  1.10 (s, 6H, 2 x CH3), 1.23 (s, 6H, 2 x CH3),
2.17–2.48 (m, 8H, 4 x CH2), 5.54 (s, 1H, CH), 7.08–7.28 (m, 5H, Ar), 11.91 (s, 1H, OH).
1.2.
2,2'-(2-nitrophenylmethylene)bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one)
(3b): The reaction was carried out according to the general experimental procedure using 2nitrobenzaldehyde (100 mg, 0.0006 mole), 5,5-dimethyl-1,3-cyclohexanedione (170 mg,
0.0013 mole), and SmCl3 (16.9 mg, 10 mol%) in water (1 mL). Conditions: room temperature
in 30 minutes. The title compound 3b was obtained (251 mg, 91%) as a solid. The spectral
data for the compound 3b was in agreement with the values already reported in the literature
[2] Mp: 244-246 0C. 1H NMR (400 MHz, CDCl3):  1.01 (s, 6H, 2 x CH3), 1.15 (s, 6H, 2 x
CH3), 2.17–2.47 (m, 8H, 4 x CH2), 6.03 (s, 1H, CH), 7.23–7.55 (m, 4H, Ar), 11.58 (s, 1H,
OH).
1.3. 2,2'-(3-nitrophenylmethylene)bis(3-hydroxy-5,5- dimethyl-2-cyclohexene-1-one)
(3c): The reaction was carried out according to the general experimental procedure using 3nitrobenzaldehyde (100 mg, 0.0006 mole ), 5,5-dimethyl-1,3-cyclohexanedione (170 mg,
0.0013 mole) and SmCl3 (16.9 mg, 10 mol%) in water (1 mL). Conditions: room temperature,
30 minutes. The title compound 3c was obtained (251 mg, 91%) as a white solid. The spectral
data for the compound 3c was in agreement with the values already reported in the literature
[1]. Mp: 201-203 0C. 1H NMR (400 MHz, CDCl3):  1.05 (s, 6H, 2 x CH3), 1.20 (s, 6H, 2 x
CH3), 2.24–2.45 (m, 8H, 4 x CH2), 5.47 (s, 1H, CH), 7.32–7.98 (m, 4H, Ar), 11.79 (s, 1H,
OH).
1.4.
2,2'-(4-nitrophenylmethylene)bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one)
(3d): The reaction was carried out according to the general experimental procedure using 4nitrobenzaldehyde (100 mg, 0.0006 mole), 5,5-dimethyl-1,3-cyclohexanedione (170 mg,
0.0013 mole) and SmCl3 (16.9 mg, 10 mol%) in water (1 mL). Conditions: room temperature,
30 minutes. The title compound 3d was obtained (251 mg, 91%) as a solid. The spectral data
for the compound 3d was in agreement with the values already reported in the literature [1].
Mp: 194-196 0C. 1H NMR (400 MHz, CDCl3):  1.04 (s, 6H, 2 x CH3), 1.16 (s, 6H, 2 x CH3),
2.24–2.44 (m, 8H, 4 x CH2), 5.57 (s, 1H, CH), 7.03-7.51(m, 4H, Ar), 11.87 (s, 1H, OH).
1.5.
2,2'-(2-bromophenylmethylene)bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one)
(3e): The reaction was carried out according to the general experimental procedure using 2bromobenzaldehyde (100 mg, 0.0005 mole ), 5,5-dimethyl-1,3-cyclohexanedione (138 mg,
S3
0.0010 mole) and SmCl3 (13.8 mg, 10 mol%) in water (1 mL). Conditions: room temperature,
25 minutes. The title compound 3e was obtained (241 mg, 97%) as a solid. The spectral data
for the compound 3e was in agreement with the values already reported in the literature [3].
Mp: 238-240 0C. 1H NMR (400 MHz, CDCl3):  1.16 (s, 12H, 4 x CH3), 2.23–2.45 (m, 8H, 4
x CH2), 5.47 (s, 1H, CH), 7.06 (d, J = 10.4 Hz, 2H, Ar), 8.03 (d, J = 8.8 Hz, 2H, Ar), 11.73
(s, 1H, OH).
1.6. 2,2'-(2-chlorophenylmethylene)bis(3-hydroxy-5,5- dimethyl-2-cyclohexene-1-one)
(3f): The reaction was carried out according to the general experimental procedure using 2chlorobenzaldehyde (100 mg, 0.0007 mole), 5,5-dimethyl-1,3-cyclohexanedione (182 mg,
0.0014 mole) and SmCl3 (18.3 mg, 10 mol%) in water (1 mL). Conditions: room temperature,
20 minutes. The title compound 3f was obtained (276 mg, 95%) as a solid. The spectral data
for the compound 3f was in agreement with the values already reported in the literature [1].
Mp: 200-202 0C. 1H NMR (400 MHz, CDCl3):  0.92 (s, 12H, 4 x CH3), 2.14 (s, 8H, 4 x
CH2), 5.42 (s, 1H, CH), 6.85–7.15 (m, 4H, Ar).
1.7. 2,2'-(4-chlorophenylmethylene)bis(3-hydroxy-5,5- dimethyl-2-cyclohexene-1-one)
(3g) : The reaction was carried out according to the general experimental procedure using 4chlorobenzaldehyde (100 mg, 0.0007 mole), 5,5-dimethyl-1,3-cyclohexanedione (182 mg,
0.0014 mole ) and SmCl3 (18.3 mg, 10 mol%) in water (1 mL). Conditions: room
temperature, 20 minutes. The title compound 3g was obtained (276 mg, 95%) as a solid. The
spectral data for the compound 3g was in agreement with the values already reported in the
literature [1].
Mp: 142-144 0C. 1H NMR (400 MHz, CDCl3):  1.02 (s, 6H, 2 x CH3), 1.14 (s, 6H, 2 x CH3),
2.21–2.41 (m, 8H, 4 x CH2), 5.40 (s, 1H, CH), 6.95 (d, J = 8.4 Hz, 2H, Ar), 7.14 (d, J = 8.4
Hz, 2H, Ar), 11.80 (s, 1H, OH).
1.8.
2,2'-(4-methylphenylmethylene)bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one)
(3h): The reaction was carried out according to the general experimental procedure using 4methylbenzaldehyde (100 mg, 0.0008 mole), 5,5-dimethyl-1,3-cyclohexanedione (213 mg,
S4
0.0014 mole) and SmCl3 (21 mg, 10 mol%) in water (1 mL). Conditions: room temperature,
30 minutes. The title compound 3h was obtained (306 mg, 95%) as a solid. The spectral data
for the compound 3h was in agreement with the values already reported in the literature [1].
Mp: 139-141 0C.1H NMR (400 MHz, CDCl3):  1.02 (s, 6H, 2 x CH3), 1.15 (s, 6H, 2 x CH3),
2.22 (s, 3H, CH3), 2.25–2.40 (m, 8H, 4 x CH2), 5.42 (s, 1H, CH), 6.91 (d, J = 8.0 Hz, 2H,
Ar), 7.19 (d, J = 8.0 Hz, 2H, Ar), 11.83 (s, 1H, OH).
1.9. 2,2'-(4-methoxyphenylmethylene)bis(3-hydroxy-5,5- dimethyl-2-cyclohexene-1-one)
(3i): The reaction was carried out according to the general experimental procedure using 4methoxybenzaldehyde (100 mg, 0.0007 mole), 5,5-dimethyl-1,3-cyclohexanedione (188 mg,
0.0014 mole) and SmCl3 (18.8 mg, 10 mol%) in water (1 mL) .Conditions: room temperature,
30 minutes. The title compound 3i was obtained (242 mg, 82%) as a solid. The spectral data
for the compound 3i was in agreement with the values already reported in the literature [1].
Mp: 146-148 0C. 1H NMR (400 MHz, CDCl3):  1.02 (s, 6H, 2 x CH3), 1.15 (s, 6H, 2 x
CH3), 2.21–2.40 (m, 8H, 4 x CH2), 3.70 (s, 3H, OCH3), 5.41 (s, 1H, CH), 6.75 (d, J = 8.8 Hz,
2H, Ar), 6.93 (d, J = 8.0 Hz, 2H, Ar), 11.84 (s, 1H, OH).
1.10. 2,2'-(4-hydroxyphenylmethylene)bis(3-hydroxy-5,5- dimethyl-2-cyclohexene-1-one)
(3j): The reaction was carried out according to the general experimental procedure using 4hydroxybenzaldehyde (100 mg, 0.0008 mole), 5,5-dimethyl-1,3-cyclohexanedione (210 mg,
0.0016 mole ) and SmCl3 (21 mg, 10 mol%) in water (1 mL). Conditions: room temperature,
30 minutes. The title compound 3j was obtained (281mg, 88%) as a solid. The spectral data
for the compound 3j was in agreement with the values already reported in the literature [1].
Mp: 188-190 0C. 1H NMR (400 MHz, CDCl3):  1.02 (s, 6H, 2 x CH3), 1.49 (s, 6H, 2 x CH3),
2.21–2.40 (m, 8H, 4 x CH2), 5.39 (s, 1H, CH), 6.64 (d, J = 8 Hz, 2H, Ar), 6.84 (d, J = 8.4
Hz, 2H, Ar), 11.81 (s, 1H, OH).
1.11. 2,2'-(4-hydroxy-3-methoxyphenylmethylene)bis(3-hydroxy-5,5-dimethyl-2cyclohexene-1-one) (3k): The reaction was carried out according to the general experimental
procedure using 4-hydroxy-3-methoxybenzaldehyde (100 mg, 0.0006 mole), 5,5-dimethyl1,3-cyclohexanedione (168 mg, 0.0013 mole) and SmCl3 (16.8 mg, 10mol %) in water (1
mL). Conditions: room temperature, 15 minutes. The title compound 3k was obtained (259
mg, 94%) as a solid. The spectral data for the compound 3k was in agreement with the values
S5
already reported in the literature [1]. Mp: 193-195 0C. 1H NMR (400 MHz, CDCl3):  1.03
(s, 6H, 2 x CH3), 1.16 (s, 6H, 2 x CH3), 2.22–2.39 (m, 8H, 4 x CH2), 3.69 (s, 3H, OCH3),
5.42 (s, 1H, CH), 6.49–6.74 (m, 3H, Ar), 11.90 (s, 1H, OH).
1.12. 2,2'-(3,4-dimethoxyphenylmethylene)bis(3-hydroxy-5,5- dimethyl-2-cyclohexene-1one) (3l): The reaction was carried out according to the general experimental procedure using
3,4-dimethoxybenzaldehyde (100 mg, 0.0006 mole), 5,5-dimethyl-1,3-cyclohexanedione
(154 mg, 0.0012 mole) and SmCl3 (15.4 mg, 10 mol%) in water (1 mL). Conditions: room
temperature, 25 minutes. The title compound 3l was obtained (242 mg, 96%) as a solid. The
spectral data for the compound 3l was in agreement with the values already reported in the
literature [1]. Mp:178-180 0C. 1H NMR (400 MHz, CDCl3):  1.28 (s, 12H, 4 x CH3), 2.55 (s,
8H, 4 x CH2), 3.85-3.92 (6H, 2 x OCH3), 6.06 (s, 1H, CH), 6.69–7.11 (m, 3H, Ar).
1.13. 2,2'-(3,4,5-trimethoxyphenylmethylene)bis(3-hydroxy-5,5- dimethyl-2-cyclohexene1-one) (3m): The reaction was carried out according to the general experimental procedure
using 3,4,5-trimethoxybenzaldehyde (100 mg, 0.0005 mole ), 5,5-dimethyl-1,3 cyclohexanedione (154 mg, 0.0012 mole) and SmCl3 (13 mg, 10 mol%) in water (1 mL) .
Conditions: room temperature, 15 minutes. The title compound 3m was obtained (219 mg,
93%) as a solid. The spectral data for the compound 3m was in agreement with the values
already reported in the literature [4]. Mp: 203-205 0C. 1H NMR (400 MHz, CDCl3):  1.05
(s, 6H, 2 x CH3), 1.17 (s, 6H, 2 x CH3), 2.28–2.35 (m, 8H, 4 x CH2), 3.68 (s, 6H, 2 x OCH3),
3.74 (s, 3H, OCH3), 5.42 (s, 1H, CH), 6.27 (s, 2H, Ar), 11.96 (s, 1H, OH).
1.14. 2,2'-( furan-2-ylmethylene)bis(3-hydroxy-5,5- dimethyl-2-cyclohexene-1-one) (3n):
The reaction was carried out according to the general experimental procedure using 2Furaldehyde (100 mg 0.0014 mole), 5,5-dimethyl-1,3-cyclohexanedione (266 mg, 0.0020
mole) and SmCl3 (26.7 mg, 10 mol%) in water (1 mL). Conditions: room temperature, 20
minutes .The title compound 3n was obtained (351 mg, 93%) as a solid. The spectral data for
the compound 3n was in agreement with the values already reported in the literature [3].
Mp: 139-141 0C. 1H NMR (400 MHz, CDCl3):  1.10 (d,J=30.8Hz,12H, 2 x CH3), 2.36 (s,
8H, 4 x CH2), 5.39 (s, 1H, CH), 5.95 (s, 1H, CH), 6.30 (s, 1H, CH), 7.26 (s, 1H, CH), 12.17
(s, 1H, OH).
S6
1.15. 2,2'-(3-phenylprop-2-ene-1,1-diyl)bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one)
(3 o): The reaction was carried out according to the general experimental procedure using
cinnamaldehyde (100 mg, 0.0007 mole) 5,5-dimethyl-1,3 cyclohexanedione (194 mg, 0.0015
mole ) and SmCl3 (19.4 mg,10 mol%) in water (1 mL). Conditions: room temperature, 25
minutes. The title compound 3o was obtained (289 mg, 96%) as a solid. The spectral data for
the compound 3o was in agreement with the values already reported in the literature [5].
Mp: 213-215 0C.1H NMR (400 MHz, CDCl3):  1.00 (s, 6H, 2 x CH3), 1.04 (s, 6H, 2 x CH3),
2.19–2.32 (m, 8H, 4 x CH2), 4.82 (s, 1H, CH), 6.44 (dd, J=11.2Hz, 2H, =CH), 7.11-7.25 (m,
5H, Ar), 12.14 (s, 1H, OH).
General Procedure B:
2. General Procedure for the Preparation of 3,3,6,6-Tetramethyl-9-aryl-3,4,5,6,7,9hexahydro-2H-xanthene-1,8-dione (4) :
To a solution of an aldehyde (1 mole) and 5,5-dimethyl-1,3-cyclohexanedione (2 mole ) in
1200 C and SmCl3 (20 mol%) was added and stirred at 120 0C. The progress of the reaction
was monitored by TLC (Silica gel, 7:3, Hexane:EtOAc), after completion of the reaction, it
was cooled to room temperature and water (5mL) was added to the reaction mixture, solid
separated was filtered washed with water (5 mL) and dried under vacuum to get the desired
Xanthenedione derivative.
2.1.
3,3,6,6-tetramethyl-9-phenyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione
(4a): The reaction was carried out according to the general experimental procedure using
benzaldehyde (100 mg, 0.0009 mole ),
5,5-dimethyl 1,3-cyclohexanedione (241 mg, 0.0018
mole), SmCl3 (48.4 mg, 20 mol%). Conditions: 120 0C, 9 h. The title compound 4a was
obtained (328 mg, 98%) as a solid. The spectral data for the compound 4a was in agreement
with the values already reported in the literature [6]. Mp: 203-205 0C. 1H NMR (400 MHz,
CDCl3):  0.98 (s, 6H, 2 x CH3), 1.10 (s, 6H, 2 x CH3), 2.21 (q, J=12Hz, 4H, 2 x CH2),
2.46(s, 4H, 2 x CH2), 4.74 (s, 1H, CH), 7.09 (t,J=14.4Hz, 1H, Ar), 7.23 (t,J=16Hz, 2H, Ar),
7.27 (d,J=12Hz, 2H, Ar).
13
C NMR: (CDCl3, 100 MHz) δ: 27.33, 29.27, 31.83, 32.2, 40.87,
50.74, 115.67, 126.36, 128.04, 128.37, 144.08, 162.24, 196.37.
S7
2.2.
3,3,6,6-tetramethyl-9-(2-nitrophenyl)-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-
dione (4b):
The reaction was carried out according to the general experimental procedure using 2nitrobenzaldehyde (100 mg, 0.0006 mole), 5,5-dimethyl-1,3-cyclohexanedione (170 mg,
0.0013 mole ) and SmCl3 (33.9 mg, 20 mol%) . Conditions: 120 0C, 10 h. The title compound
4b was obtained (260 mg, 98%) as a solid. The spectral data for the compound 4b was in
agreement with the values already reported in the literature [6]. Mp:246-248 0C. 1H NMR
(400 MHz, CDCl3):  1.00 (s, 6H, 2 x CH3), 1.09 (s, 6H, 2 x CH3), 2.20 (q,J=12.4Hz, 4H, 2 x
CH2), 2.46(s, 4H, 2 x CH2), 5.50 (s, 1H, CH), 7.24 (d, J=5.6Hz, 2H, Ar), 7.37-7.45 (m, 2H,
Ar),7.74 (d,J=8Hz, 1H, Ar).
2.3.
3,3,6,6-tetramethyl-9-(3-nitrophenyl)-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-
dione (4c): The reaction was carried out according to the general experimental procedure
using 3-nitrobenzaldehyde (100 mg, 0.0006 mole), 5,5-dimethyl-1,3-cyclohexanedione (170
mg, 0.0013 mole) and SmCl3 (33.9 mg, 20 mol%). Conditions: 120 0C, 10h. The title
compound 4c was obtained (257 mg, 97%) as a solid. The spectral data for the compound 4c
was in agreement with the values already reported in the literature [6]. Mp: 171-173 0C. 1H
NMR (400 MHz, CDCl3):  1.00 (s, 6H, 2 x CH3), 1.11 (s, 6H, 2 x CH3), 2.27 (q, J=16.8Hz,
4H, 2 x CH2), 2.50 (s, 4H, 2 x CH2), 4.83 (s, 1H, CH), 7.42 (t, J=16.6Hz, 1H, Ar), 7.83 (d,
J=8Hz, 1H, Ar), 8.00 (t, J=10.4Hz, 2H, Ar).
13
C NMR (CDCl3, 100 MHz) : δ 27.31, 29.20,
32.08, 32.26, 40.84, 50.62, 114.55, 121.69, 122.48, 128.8, 146.28, 148.33, 163.02, 196.4.
2.4.
3,3,6,6-tetramethyl-9-(4-nitrophenyl)-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-
dione (4d):
The reaction was carried out according to the general experimental procedure using 4nitrobenzaldehyde (100 mg, 0.0006mole ), 5,5-dimethyl-1,3-cyclohexanedione (170 mg,
0.0013 mole ) and SmCl3 (33.9 mg, 20 mol%). Conditions: Conditions: 120 0C, 12 h. The title
compound 4d was obtained (257 mg, 97%) as a solid. The spectral data for the compound 4d
was in agreement with the values already reported in the literature [6].
Mp: 225-226 0C. 1H NMR (400 MHz, CDCl3):  0.99 (s, 6H, 2 x CH3), 1.11 (s, 6H, 2 x CH3),
2.18 (q, J=19.6Hz, 4H, 2 x CH2), 2.49 (s, 4H, 2 x CH2), 4.82 (s, 1H, CH), 7.47 (d, J=5.2Hz,
2H, Ar), 8.10 (d,J=4.8 Hz, 2H, Ar).
13
C NMR (CDCl3,100 MHz) : δ 27.27, 29.25, 32.23,
32.35, 40.84, 50.59, 114.54, 123.44, 129.35, 146.48, 151.49, 162.93, 196.26.
S8
2.5. 9-(2-bromophenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)dione (4e): The reaction was carried out according to the general experimental procedure
using 2-bromobenzaldehyde (100 mg, 0.0054 mole ), 5,5-dimethyl-1,3-cyclohexanedione
(138 mg, 0.0010 mole ) and SmCl3 (27.7 mg, 20 mol%). Conditions: 120 0C, 8 h. The title
compound 4e was obtained (230 mg, 98%) as a solid. The spectral data for the compound 4e
was in agreement with the values already reported in the literature [4]. Mp: 226-229 0C. 1H
NMR (400 MHz, CDCl3):  1.01 (s, 6H, 2 x CH3), 1.09 (s, 6H, 2 x CH3), 2.19 (q, J=12.4Hz,
4H, 2 x CH2), 2.44 (s, 4H, 2 x CH2), 5.01 (s, 1H, CH), 6.95 (t,J=6.4Hz, 1H, Ar), 7.18
(t,J=6.8Hz, 1H, Ar), 7.32 (s, 1H, Ar), 7.42 (d,J=7.2Hz, 1H, Ar).
2.6. 9-(2-chlorophenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)dione (4f): The reaction was carried out according to the general experimental procedure
using 2-chlorobenzaldehyde (100 mg, 0.0007 mole), 5,5-dimethyl-1,3-cyclohexanedione (182
mg, 0.0014 mole) and SmCl3 (36.6 mg, 20 mol%). Conditions: 120 0C, 8 h. The title
compound 4f was obtained (272 mg, 98%) as a solid. The spectral data for the compound 4f
was in agreement with the values already reported in the literature [6]. Mp: 230-232 0C. 1H
NMR (400 MHz, CDCl3):  1.01 (s, 6H, 2 x CH3), 1.09 (s, 6H, 2 x CH3), 2.20 (q, J=12Hz,
4H, 2 x CH2), 2.44 (s, 4H, 2 x CH2), 4.99 (s, 1H, CH), 7.06 (t, J=7.6Hz, 1H, Ar), 7.16 (t,
J=7.2Hz, 1H, Ar), 7.23 (d, J=8Hz, 1H, Ar),7.44 (d, J=7.2Hz, 1H, Ar). 13C NMR (CDCl3,100
MHz) :δ 27.36, 29.28, 32.02, 40.81, 50.69, 113.67, 126.33, 127.81, 130.16, 133.42, 162.97,
196.5.
2.7. 9-(4-chlorophenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)dione (4g): The reaction was carried out according to the general experimental procedure
using 4-chlorobenzaldehyde (100 mg, 0.0007 mole), 5,5-dimethyl-1,3-cyclohexanedione (182
mg, 0.0014mole ) and SmCl3 (36.6mg, 20 mol%) . Conditions: 120 0C, 9 h. The title
compound 4g was obtained (269 mg, 97%) as a solid. The spectral data for the compound 4g
was in agreement with the values already reported in the literature [6]. Mp: 230-233 0C. 1H
NMR (400 MHz, CDCl3):  0.98 (s, 6H, 2 x CH3), 1.10 (s, 6H, 2 x CH3), 2.18 (q, J=13.6 Hz,
4H, 2 x CH2), 2.46 (s, 4H, 2 x CH2), 4.70 (s, 1H, CH), 7.17–7.26 (m, 4H, Ar). 13C NMR
(CDCl3,100 MHz) :δ 27.29, 29.28, 31.46, 32.20, 40.84, 50.69, 115.27, 128.22, 129.77,
132.03, 142.69, 162.41, 196.35.
2.8. 3,3,6,6-tetramethyl-9-p-tolyl-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione (4h):
S9
The reaction was carried out according to the general experimental procedure using 4methylbenzaldehyde (100 mg, 0.0008 mole), 5,5-dimethyl-1,3-cyclohexanedione (213 mg,
0.0014 mole) and SmCl3 (42.7 mg, 20mol%). Conditions: 120 0C, 8h. The title compound 4h
was obtained (301 mg, 98%) as a solid. The spectral data for the compound 4h was in
agreement with the values already reported in the literature [6]. Mp: 212-214 0C. 1H NMR
(400 MHz, CDCl3):  0.99 (s, 6H, 2 x CH3), 1.10 (s, 6H, 2 x CH3), 2.20 (q, J=411.6Hz, H, 2 x
CH2), 2.24 (s, 3H, CH3), 2.45 (s, 4H, 2 x CH2), 4.70 (s, 1H, CH), 7.02 (d,J=8Hz, 2H, Ar),
7.18 (d,J=8Hz, 2H, Ar).
C NMR (CDCl3,100 MHz) : δ 21.05, 27.38, 29.26, 31.43, 32.2,
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40.88, 50.76, 115.77, 128.24, 128.79, 135.77, 141.19, 162.09, 196.43.
2.9. 9-(4-methoxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene1,8(2H)-dione (4i): The reaction was carried out according to the general experimental
procedure using 4- methoxybenzaldehyde (100 mg, 0.0007 mole), 5,5dimethyl1,3cyclohexanedione (188 mg, 0.014 mole) and SmCl3 (37.7 mg, 20 mol%) . Conditions: 120
0
C, 10 h. The title compound 4i was obtained (274 mg, 97%) as a solid. The spectral data for
the compound 4i was in agreement with the values already reported in the literature [7].
Mp:242-245 0C. 1H NMR (400 MHz, CDCl3):  0.99 (s, 6H, 2 x CH3), 1.09 (s, 6H, 2 x CH3),
2.18 (q, J=10.8 Hz, 4H, 2 x CH2), 2.45 (s, 4H, 2 x CH2), 3.73 (s, 3H, OCH3), 4.69 (s, 1H,
CH), 6.76 (d, J=8.8Hz, 2H, Ar), 7.21 (d, J=8.8Hz, 2H, Ar). 13C NMR (CDCl3,100 MHz) : δ
27.34, 29.27, 30.96, 32.2, 40.86, 50.76, 55.11, 113.46, 115.79, 129.3, 136.48, 157.94, 162.06,
196.5.
2.10. 9-(4-hydroxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene1,8(2H)-dione (4j): The reaction was carried out according to the general experimental
procedure using 4-hydroxybenzaldehyde (100 mg, 0.0008 mole), 5,5-dimethyl-1,3-
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cyclohexanedione (210 mg, 0.0016 mole) and SmCl3 (42 mg, 20 mol%) . Conditions: 120 0C,
9 h. The title compound 4j was obtained (298 mg, 98%) as a solid. The spectral data for the
compound 4j was in agreement with the values already reported in the literature [6]. Mp:
244-246 0C. 1H NMR (400 MHz, CDCl3):  0.99 (s, 6H, 2 x CH3), 1.09 (s, 6H, 2 x CH3), 2.21
(q, J=8.8Hz, 4H, 2 x CH2), 2.45 (s, 4H, 2 x CH2), 4.67 (s, 1H, CH), 6.61 (d, J=8Hz, 2H, Ar),
7.11(d, J=8Hz, 2H, Ar).
C NMR (CDCl3,100 MHz): δ 27.37, 29.19, 30.96, 32.26, 40.85,
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50.76, 115.18, 115.85, 129.39, 135.83, 154.5, 162.34, 197.08.
2.11. 9-(4-hydroxy-3-methoxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1Hxanthene-1,8(2H)-dione (4k): The reaction was carried out according to the general
experimental procedure using 4-hydroxy-3-methoxybenzaldehyde (100 mg, 0.0006 mole ),
5,5-dimethyl-1,3-cyclohexanedione (168 mg, 0.0013 mole ) and SmCl3 (33.7 mg, 20 mol%) .
Conditions: 120 0C, 8 h. The title compound 4k was obtained (258 mg, 98%) as a solid. The
spectral data for the compound 4k was in agreement with the values already reported in the
literature [7]. Mp: 224-225 0C. 1H NMR (400 MHz, CDCl3):  1.00 (s, 6H, 2 x CH3), 1.10 (s,
6H, 2 x CH3), 2.20 (q, J=7.2Hz, 4H, 2 x CH2), 2.45 (s, 4H, 2 x CH2), 3.89 (s, 3H, OCH3),
4.66 (s, 1H, CH), 5.46 (s, 1H, OH), 6.58 (d, J=8Hz,1H, Ar), 6.74 (d, J=8Hz,1H, Ar), 7.00 (s,
1H, Ar).
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C NMR (CDCl3, 100 MHz): δ 27.28, 29.31, 31.30, 32.20, 40.86, 50.77, 55.88,
112.26, 113.91, 115.81, 120.01, 136.46, 144, 145.87, 162.08.
2.12.
9-(3,4-dimethoxyphenyl)-3,3,6,6-tetramethyl-3,4,5,6,7,9-hexahydro-1H-xanthene-
1,8(2H)-dione (4l): The reaction was carried out according to the general experimental
procedure using 3,4-dimethoxybenzaldehyde (100
mg, 0.0006
mole)
5,5-dimethyl-1,3-
cyclohexanedione (154 mg, 0.0012 mole ) and SmCl3 (30.9 mg, 20 mol%) . Conditions: 120
0
C, 9 h. The title compound 4l was obtained (233 mg, 97%) as a solid. The spectral data for
the compound 4l was in agreement with the values already reported in the literature [8]. Mp:
179-181 0C. 1H NMR (400 MHz, CDCl3):  1.00 (s, 6H, 2 x CH3), 1.10 (s, 6H, 2 x CH3),
2.20 (q, J=7.6Hz, 4H, 2 x CH2), 2.46 (s, 4H, 2 x CH2), 3.79 (s, 3H, OCH3), 3.85 (s,3H,
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OCH3), 4.70 (s, 1H, CH), 6.70–6.77 (m, 2H, Ar), 6.90 (s, 1H, Ar).
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C NMR (CDCl3, 100
MHz) : δ 27.26, 29.34, 31.22, 32.19, 40.89, 50.75, 55.75, 55.88, 110.83, 112.29, 115.76,
120.11, 136.98, 147.46, 148.45, 162.11, 196.5.
2.13. 3,3,6,6-tetramethyl-9-(3,4,5-trimethoxyphenyl)-3,4,5,6,7,9-hexahydro-1Hxanthene-1,8(2H)-dione (4m): The reaction was carried out according to the general
experimental procedure using 3,4,5-trimethoxybenzaldehyde (100 mg, 0.0005 mole ), 5,5dimethyl-1,3-cyclohexanedione (154 mg, 0.0010mole) and SmCl3 (26.1 mg, 20 mol%) .
Conditions: 120 0C, 10 h. The title compound 4m was obtained (222 mg, 98%) as a solid.
The spectral data for the compound 4m was in agreement with the values already reported in
the literature [6]. Mp: 186-188 0C. 1H NMR (400 MHz, CDCl3):  1.03 (s, 6H, 2 x CH3), 1.11
(s, 6H, 2 x CH3), 2.23–2.24 (m, 8H, 4 x CH2), 3.77 (s, 3H, OCH3), 3.80 (s, 6H, 2 x OCH3),
4.71(s, 1H, CH), 6.51 (s, 2H, Ar). 13C NMR (CDCl3, 100 MHz) : δ 27.19, 29.37, 31.8, 32.19,
40.9, 50.73, 56.09, 60.7, 105.7, 115.57, 136.55, 139.73, 152.79, 162.35, 196.52.
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