反应详情

A flame-dried 100 mL, three-necked flask with magnetic stirring bar was charged under argon with 2.0 g (10.2 mmol) of (2R,3E,6R)-6,10-dimethyl-3,9-undecadien-2-ol [(2R,6R)/(2S,6R)=90;10 by GC diastereomer analysis of butyrate derivative]. Then, after cooling in an ice-bath, 1.5 g (1.4 mL, 15 mmol) of acetic anhydride, 1.58 g (1.6 mL, 20 mmol) of dry pyridine and 12.3 mg (0.1 mmol) of 4-N,N-dimethylaminopyridine were added, and the reaction was stirred for 75 minutes at ambient temperature. Work-up as described in Example 9 followed by Kugelrohr distillation at ca. 110°/0.25 mm afforded 2.35 g (99%) of (2R,3E,6R)-6,10-dimethyl-3,9-undecadien-2-ol acetate as colorless liquid; GC purity 90%; [α]D25 =+47.17° (5.3% in CHCl3).

1. temperatureThen, after cooling in an ice-bath
2. distillationfollowed by Kugelrohr distillation at ca. 110°/0.25 mm