Supporting Information
“Synthesis and Radical Polymerization of Methacrylate Endowed with Bicyclobis(γbutyrolactone) Moiety through Methylene Linker”
by Ryu Yamasaki, Atsushi Sudo, and Takeshi Endo
Synthesis of anhydrides 2 (Scheme S1)
A typical procedure: 6-Chlorohexanoic acid (5.00 g, 33.2 mmol) was dissolved with dry THF
(25 mL) and pyridine (2.7 mL) and stirred for 30 min. To the solution was added oxalyl chloride
(1.44 mL, 16.8 mmol) dropwise at 0 ºC, and stirred for additional 2 h at room temperature. The
reaction was quenched by adding water (30 mL) to the solution and THF was removed under
reduced pressure. The mixture was extracted with AcOEt (60 mL), and the organic layer was
washed with 1 N HCl (30 mL), sat. NaHCO3 aq. (30 mL x 2), and brine (30 mL), followed by
drying over Na2SO4. After filtration, the solution was concentrated under reduced pressure to
obtain crude 6-chlorohexanoic anhydride (2d) (3.94 g, 84%) as a colorless oil, which was used
without purification.
The other anhydrides 2b and 2c were prepared similarly from the corresponding carboxylic
acids. The spectroscopic data of 2b were identical to those reported.S1 Anhydride 2c was
obtained as a colorless oil in 77% yield. For the synthesis of 2a, Et2O was used as the solvent
and obtained as colorless oil in 92% yield. The spectroscopic data of 2a were identical to those
reported.S2
5-Chloroheptanoic anhydride (2c): Colorless oil; 1H NMR (400 MHz, CDCl3, δ): 3.57 (t, 2H, J =
6.0 Hz; OH-C(=O)CH2-), 2.51 (t, J = 6.8 Hz, 2H; ClCH2-), 1.83–1.87 (m, 4H); 13C NMR (100 MHz,
CDCl3, δ): 168.9 (C=O), 44.3 (Cl-C-), 34.3 (-C-C(=O)-O), 31.4(Cl-CH2-CH2-), 21.5(Cl-CH2-CH2-CH2-);
IR (neat): ν = 2958 (m), 1814 (s), 1745 (s), 1448 (w), 1411 (w), 1357 (w), 1278 (w), 1026 (s), 893
(w), 728 cm−1 (w).
6-Chlorohexanoic anhydride (2d): 1H NMR (400 MHz, CDCl3, δ): 3.55 (t, 2H, J = 6.7 Hz; ClCH2), 2.48 (t, J = 7.2 Hz, 2H; O-C(=O)CH2-), 1.79 (m, 2H), 1.68 (m, 2H), 1.52 (m, 2H); 13C NMR (100
MHz, CDCl3, δ): 169.2 (C=O), 44.6 (Cl-C-), 35.0 (-C-C(=O)-O), 32.1(Cl-CH2-CH2-), 26.1(Cl-CH2-CH2CH2-), 23.4(O-C(=O)-CH2-CH2-); IR (neat): ν = 2941 (m), 2867 (w), 1816 (s), 1747 (s), 1460 (w),
1412 (w), 1361 (w), 1311 (w), 1034 (s), 922 (w), 734 cm−1 (w).
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Scheme S1 Synthesis of acid anhydrides 2.
Synthesis of 3-benzyloxypropionic acid (BPA) (Scheme S2)
To a mixture of methanol (40 mL) and hydrochloric acid (12 N, 3.2 mL), thionyl chloride (3.8
mL, 52.3 mmol) was added dropwise for 10 min at 0 ºC. To the mixture, 3benzyloxypropionitrile (17.0 g, 105 mmol) was added at rt dropwise for 20 min, and then
heated with refluxing for 11 h. After being cooled to rt, the mixture was filtered and washed
with MeOH. To the filtrate, sodium carbonate (3 g) was added. The mixture was filtered and
the filtrate was concentrated under reduced pressure. The resulting residue was dissolved in
toluene (20 mL), filtered, and the filtrate was concentrated under reduced pressure to obtain
crude methyl 3-benzyloxypropionate.
Methyl 3-benzyloxypropionate thus prepared was dissolved in THF (30 mL), and to this
solution, a solution of LiOH-H2O (5.0 g, 12 mmol) in H2O (20 mL) was added. Stirred for 17 h at
rt, the mixture was evaporated, and extracted with Et2O (50 mL x 3), dried over Na2SO4,
filtered, then evaporated to afford BPA (9.43 g, 50 %) as a colorless oil. The spectroscopic data
were identical with those reported in a literature.S2
Scheme S2 Synthesis of 3-benzyloxypropionic acid (BPA).
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Figure S1 SEC Chromatograms of polymethacrylates 6a-6d.
References
S1. T. Sakai, K. Iwata, M. Utaka, A. Takeda, Bull. Chem. Soc. Jpn. 1987, 60, 1161–1162.
S2. R. A. Zarkesh, M. D. Hopkins, R. F. Jordan, Eur. J. Inorg. Chem. 2014, 32, 5491–5494.
S3. L. V. Heumann, G. E. Keck. Org. Lett. 2007, 9, 1951–1954.
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