反应详情

The reaction of methyl 2-ethyl-3-methylbutyrate (23.76 g, 165 mmol), prepared as in Lion C, Dubois J E (1981) supra., with allyl bromide (31.34 g, 259 mmol) in the presence of lithium diisopropylamide (prepared by treating diisopropylamine (25.05 g, 248 mmol) with butyllithium in hexanes (2.5 M, 94.4 mL, 236 mmol)) in THF (330 mL) and HMPA (24.7 mL, 142 mmol), as described above in the preparation of Example 7, followed by the vacuum distillation of crude product afforded the pure olefinic ester (24.85 g, 82%) as a colorless liquid: bp 92-94° C. (20 mmHg).

1. distillationfollowed by the vacuum distillation of crude product