Pyridine → Acetic Acid 7-isopropylidene-2,5-dimethyl-bicyclo[2.2.1]hept-5-en-2-ylmethyl Ester

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Reaction Steps

To a solution of (7-Isopropylidene-2,5-dimethyl-bicyclo[2.2.1]hept-5-en-2-yl)-methanol (4.32 g, 22.5 mmol), pyridine (3.55 g, 45 mmol) and DMAP (50 mg) in dichloromethane (50 ml) was added acetyl chloride (2.47 g, 31.5 mmol) with cooling. The mixture was stirred at room temperature for 1 h and was then diluted with water and extracted with pentane (3×80 ml). the organic phase was washed with 1N HCl, water and brine, dried (MgSO4) and concentrated in vacuo. The residue was purified by chromatography on silica gel (hexane:MTBE=9:1) to yield 4.25 g of a colorless oil as a mixture of isomers. Odor description: cedarwood oil, carrot, verdyl, musky. 1H-NMR (CDCl3, 400 MHz): 5.93–5.72 (m, 1H), 3.94–3.73 (m, 2H), 3.10–2.78 (m, 2H), 2.09–2.03 (m, 3H), 1.85–1.53 (m, 9H1.50–1.15 (m, 2H), 1.09/0.97/0.92/0.89 (4s, 3H) ppm. GC/MS (EI): main isomer: 234 (M+, trace), 159 (3), 120 (100), 105 (46), 91 (11), 77 (7), 43 (15), IR (atr): 2927m, 2726w, 1741s, 1446m, 1369m, 1233vs, 1031s, 986m, 802m cm−1.

Provenance & Evidence