Methanol → Methyl 5-Hexenoate

Participants

Reaction Steps

Hex-5-enoic acid methyl ester was prepared as follows. Hex-5-enoic acid (2.00 g, 17.5 mmol) was dissolved in diethyl ether (8 mL) and methanol (4 mL) and cooled to 0° C. To this solution was added 2.0 M Trimethylsilyl diazomethane (9 mL) dropwise. It was noted that a yellow TMS-diazomethane solution dissipates upon stirring with the reaction mixture, and the reaction is deemed complete when the yellow color persists. Caution should be observed, as the reaction is associated with vigorous gas evolution. When the yellow color persists in the reaction mixture, TLC analysis was conducted and confirmed consumption of the acid. The solvent was evaporated under reduced pressure carefully (product is somewhat volatile) and replaced with ethyl acetate. The solution was washed with saturated NaHCO3, dried, and the filtrate was used directly in the next step. 1H NMR (400 MHz) CDCl3 δ 5.45 (m, 1H), δ 4.9 (m, 2H), δ 3.65 (s, 3H), δ 2.20 (t, 2H), δ 2.05 (m, 2H), δ 1.70 (m, 2H).

Provenance & Evidence