Supplementary Data Synthetic procedures. Oxidation of alcohol to aldehydes. Decanal and its deuteriated analogs Pyridiniumchlorochromate (72 mg, 0 .34 mmol) was added to a solution of decanol (20 mg, 0.12 mmol) (50 mg, 0.32 mmol), or a deuteriated decanol, in dichloromethane (2 mL), and the mixture was stirred for 1 h and filtered. The filtrate was washed with 1 M NaOH (2 × 1 mL), water (2 mL) and 1 M HCl (2 mL). The dichloromethane layer was separated, dried over MgSO4, and the solvent was evaporated to afford the product (16 mg, 80 %). Decanal: EI -MS: m/z (%), 156 (M+•, 2), 128 (5), 112 (20), 110 (10), 96 (20), 95 (20), 84 (15), 83 (25), 82 (30), 81 (20), 72 (5), 71 (35), 70 (20), 69 (30), 68 (35), 67 (25), 57 (100), 56 (40), 55 (60), 44 (50), 43 (50), 42 (25), 41 (80). [1-2H]decanal: EI -MS: m/z (%), 157 (M+•, 3), 129 (5), 112 (15), 110 (15), 96 (15), 95 (20), 84 (250, 83 (20), 82 (25), 81 (15), 72 (15), 71 (35), 70 (25), 69 (30), 68 (35), 67 (25), 57 (100), 56 (40), 55 (55), 44 (50), 43 (50), 42 (25), 41 (75). [2,2-2H2]decanal: EI -MS: m/z (%), 158 (M+•, 2), 130 (5), 112 (10), 110 (10), 97 (10), 96 (25) 95 (15), 85 (5), 84 ( 20), 83 (25), 82 (20), 81 (5), 72 (10), 71 (30), 70 (15), 69 (25), 68 (20), 67 (20), 57 (100), 56 (50), 55 (65), 44 (45), 43 (55), 42 (30), 41 (70). [3,3-2H2]decanal: EI -MS: m/z (%), 158 (M+•, 1), 130 (5), 114 (15), 112 (10), 97 (15), 96 (25), 95 (10), 85 (10), 84 ( 20), 83 (25), 82 (20), 72 (15), 71 (30), 70 (25), 69 (20), 68 (30), 67 (15), 57 (100), 56 (50), 55 (65), 44 (45), 43 (55), 42 (30), 41 (85). [4,4-2H2]decanal: EI -MS: m/z (%), 158 (M+•, 2), 130 (5), 114 (20), 112 (10), 97 (25), 96 (15), 95 (5), 85 (15), 84 ( 20), 83 (20), 82 (35), 72 (20), 71 (25), 70 (20), 69 (20), 68 (30), 67 (20), 57 (100), 56 (50), 55 (60), 44 (45), 43 (55), 42 (30), 41 (80). [5,5-2H2]decanal: EI -MS: m/z (%), 158 (M+•, 2), 130 (5), 114 (20), 112 (10), 97 (20), 96 (15), 95 (10), 85 (12), 84 (15), 83 (30), 82 (25), 72 (25), 71 (25), 70 (15), 69 (25), 68 (20), 67 (15), 57 (100), 56 (50), 55 (50), 44 (60), 43 (60), 42 (20), 41 (85). Decanal oxime and its deuteriated analogs 1 Decanal (15 mg, 0.1 mmol), or a deuteriated decanal, in ethanol (1 mL) was combined with NH2OH•HCl (14 mg, 0.2 mmol) in water (1 mL). A solution of Na2CO3 (21 mg, 0.2 mmol) in water (1 mL) was added dropwise, and the mixture was stirred overnight at 50 °C and concentrated under reduced pressure. Water (2 mL) was added and the reconstituted mixture was extracted with ether (2 x 1 mL). The combined ether layers were dried over Na2SO4 and evaporated to give a clear oil (15 mg, 91%). Decanal oxime: EI -MS: m/z (%), 171 (M+•, 1), 154 (5), 138 (2), 128 (2), 114 (2), 100 (5), 96 (15), 87 (10), 82 (10), 72 (20), 59 (100), 55 (20), 43 (30), 41 (50). [1-2H]Decanal oxime: EI -MS: m/z (%), 172 (M+•, 2), 155 (5), 139 (2), 129 (3), 115 (3), 110 (10), 101 (25), 96 (20), 87 (25), 82 (20), 73 (30), 60 (100), 55 (20), 43 (60), 41 (90). [2,2-2H2]Decanal oxime: EI -MS: m/z (%), 173 (M+•, 1), 156 (5), 140 (2), 130 (3), 112 (10), 98 (10), 87 (25), 84 (20), 73 (15), 61 (100), 57 (30), 55 (30), 43 (60), 41 (60). [3,3-2H2]Decanal oxime: EI -MS: m/z (%),173 (M+•, 1), 156 (5), 140 (2), 130 (3), 116 (10), 102 (20), 98 (10), 88 (20), 84 (15), 74 (20), 59 (100), 55 (30), 43 (60), 41 (50). [4,4-2H2]Decanal oxime: EI -MS: m/z (%),173 (M+•, 2), 156 (10), 140 (2), 130 (4), 116 (10), 102 (25), 98 (10), 87 (15), 84 (15), 72 (35), 60 (100), 56 (30), 43 (60), 41 (60). [5,5-2H2]Decanal oxime: EI -MS: m/z (%),173 (M+•, 2), 156 (10), 140 (2), 130 (5), 116 (10), 102 (15), 98 (10), 87 (15), 84 (10), 72 (25), 59 (100), 56 (30), 43 (60), 41 (55). Decylamine and its deuteriated analogs Decanal oxime (15 mg, 0.1 mmol), or its deuteriated analogs, in dry THF (1 mL) was added to lithium aluminum hydride (16 mg, 0.4 mmol), or lithium aluminum deuteride (18 mg, 0.4 mmol), in dry diethyl ether (1 mL). The reaction mixture was stirred at 40 °C overnight, cooled to 0 °C, and quenched with water (0.2 mL). The cooled mixture was shaken with 2 M HCl (5 mL) to dissolve the inorganic solids and the aqueous layer was discarded. The organic layer was dried over MgSO4 and evaporated to yield the product as a clear liquid. Decylamine: EI -MS: m/z (%), 157 (M+•, 5), 140 (2), 128 (3), 119 (2), 100 (10), 86 (20), 69 (10), 60 (10), 55 (20), 44 (80), 41 (100). [1,1-2H2 ]Decylamine: EI -MS: m/z (%), 159 (M+•, 10), 142 (3), 130 (3), 121 (1), 102 (10), 88 (25), 71 (10), 61 (10), 55 (25), 46 (80), 41 (100). 2 [2,2-2H2]Decylamine: EI -MS: m/z (%), 159 (M+•, 10), 142 (3), 130 (5), 121 (2), 102 (10), 88 (30), 71 (15), 61 (15), 55 (25), 45 (80), 41 (100). [3,3-2H2]Decylamine: EI -MS: m/z (%), 159 (M+•, 10), 142 (1), 130 (5), 121 (0), 102 (15), 88 (25), 71 (10), 61 (10), 55 (20), 44 (100), 41 (80). [4,4-2H2]Decylamine: EI -MS: m/z (%), 159 (M+•, 10), 142 (1), 130 (2), 121 (1), 102 (15), 88 (25), 71 (15), 60 (10), 56 (50), 44 (90), 41 (100). [5,5-2H2]Decylamine: EI -MS: m/z (%), 159 (M+•, 5), 142 (1), 130 (2), 119 (5), 100 (15), 88 (20), 71 (25), 60 (10), 56 (50), 45 (100), 41 (70). N-Decyl-p-toluenesulfonamide (1) and its deuterated analogs p-Toluenesulfonyl chloride (12 mg, 0.06 mmol) was dissolved in DCM (1 mL) and added drop wise to a solution of decylamine (10 mg, 0.06 mmol), or other amines, DCM (1 mL) and triethylamine (20 mg, 0.2 mmol) and stirred overnight. The reaction mixture was washed with 2M HCl (2 x 2 mL), followed by 2M NaOH (2 x 2 mL) dried over MgSO4, and evaporated to give a white solid (16 mg, 85%). N-Decyl-p-toluenesulfonamide (1): EI -MS: m/z (%), 311 (M+•, 3), 185 (5), 184 (90), 173 (5), 172 (40), 156 (60), 155 (100), 91 (90), 65 (20), 41 (20). N-[1,1-2H2 ]decyl-p-toluenesulfonamide: EI -MS: m/z (%), 313 (M+•, 3), 187 (5), 186 (90), 173 (5), 172 (50), 158 (40), 155 (100), 91 (85), 65 (20), 43 (20), 41 (20). N-[2,2-2H2]decyl-p-toluenesulfonamide: EI -MS: m/z (%), 313 (M+•, 5), 185 (5), 184 (90), 173 (5), 172 (30), 158 (70), 155 (100), 91 (95), 65 (20), 43 (20), 41 (15). N-[3,3-2H2]decyl-p-toluenesulfonamide: EI -MS: m/z (%), 313 (M+•, 3), 185 (10), 184 (90), 173 (15), 172 (20), 158 (60), 155 (100), 91 (90), 65 (20), 43 (20), 41 (20). N-[4,4-2H2]decyl-p-toluene sulfonamide: EI -MS: m/z (%), 313 (M+•, 3), 185 (40), 184 (90), 173 (20), 172 (15), 158 (60), 155 (100), 91 (95), 65 (20), 43 (25), 41 (20). N-[5,5-2H2]decyl-p-toluenesulfonamide: EI -MS: m/z (%), 313 (M+•, 3), 185 20), 184 (80), 173 (15), 172 (20), 158 (55), 155 (100), 91 (100), 65 (25), 43 (20), 41 (20). N-[2-octyl]-p-toluenesulfonamide: EI -MS: m/z (%), 283 (M+•, 2), 268 (5), 198 (100), 172 (5), 155 (50), 91 (40), 65 (10), 43 (10), 43 (10), 41 (10). N-[t-butyl]-p-toluenesulfonamide: EI -MS: m/z (%), 227 (M+•, 2), 212 (100), 172 (1), 155 (70), 91 (80), 65 (15), 43 (10), 41 (10). 3 N-pentyl-p-toluenesulfonamide: EI -MS: m/z (%), 241 (M+•, 2), 184 (80), 173 (5), 172 (50), 155 (100), 91 (85), 86 (25), 65 (20), 43 (20), 41 (20). 4 Supplementary Figures . . O H S N O H A m/z 276 B O O S NH2 S O O H2N Ion/Neutral Complex B Ion/Neutral Complex A m/z 276 O S NH2 O m/z 105 Supplementary Figure 1. Formation of m/z 105 ion upon collisional activation of prototonated N-phenylethyl-p-toluenesulfonamide. 5 Supplementary Figure 2. Proposed fragmentation of prototonated N- phenylethyl-ptoluenesulfonamide. 6