Water → 4-Prop-2-ynylcyclohexanecarboxylic acid

Participants

Reaction Steps

A solution of chromium trioxide (600 mg, 6.0 mmol) in 1.5 M H2SO4 (2.6 mL, 150 mmol) was cooled to 5° C. and added to a solution of 86 (280 mg, 1.84 mmol) in acetone (15 mL). The mixture was allowed to warm to room temperature and allowed to stir overnight. Isopropanol (4 mL) was added to the green/black solution, which turned light blue after 1 hr. After adding water (15 mL), the solution was extracted with CHCl3 (6×25 mL). The organic layers were pooled and concentrated in vacuo to yield a white solid. The solid was dissolved in ether (50 mL) and extracted with 1 M NaOH (2×30 mL). The basic extracts were pooled, acidified w/10% HCl, and re-extracted with ether (3×30 mL). The ether layers were combined, dried with sodium sulfate and concentrated in vacuo to yield a white solid. The product was recrystallized from acetone/water to yield 88 (222 mg, 73%) as white needles: mp 84–85° C.; 1H NMR (CDCl3) δ 2.30–2.23 (m, 1H), 2.17–2.11 (m, 2H), 2.07–2.03 (m, 2H), 1.97–1.91 (m, 3H), 1.51–1.39 (m, 3H), 1.13–1.01 (m, 2H); 13C NMR (CDCl3) δ 182.5, 83.8, 69.6, 40.7, 37.7, 32.3, 29.6, 26.5; APCI m/z (rel intensity) 165 (M−, 100).

Provenance & Evidence