Menthol → (-)-Menthyl acetoacetate

Participants

Reaction Conditions

Reaction Steps

A solution of (-)-menthol (23.0 g, 147 mmol, 1 equiv) and 1-butyl acetoacetate (20.0 ml, 121 mmol, 0.80 equiv) in toluene (50 mL) was heated at reflux for 12 h, then was cooled to 23° C. Volatiles were removed in vacuo and toluene (20 mL) and 1-butyl acetoacetate (12.2 mL, 73.5 mmol, 0.50 equiv) were added to the residue. The resulting solution was heated at reflux for 12 h, then was cooled to 23° C. The cooled reaction mixture was concentrated in vacuo and the residue was purified by distillation under reduced pressure (bp 90° C., 30 mmHg) to afford (1R,3R,4S)-p-menth-3-yl acetoacetate (1) as a low-melting solid (33.3 g, 94%). ##STR14##

Provenance & Evidence