苯甲酰氯 、 Benzoic acid (1S,2S)-2-((2R,3R,5R,6R,8S,9R,10S,11S)-3-benzyloxy-8-ethyl-9,10-dihydroxy-3,5,9,11-tetramethyl-1,7-dioxa-spiro[5.5]undec-2-yl)-1-((R)-1-methoxycarbonyl-ethyl)-propyl ester 在
sodium methylate 作用下,
以
甲醇 为溶剂,
反应 2.0h,
以83%的产率得到(E)-(S)-4-((2R,3R,5R,6R,8S,9R,10S,11S)-3-Benzyloxy-8-ethyl-9,10-dihydroxy-3,5,9,11-tetramethyl-1,7-dioxa-spiro[5.5]undec-2-yl)-2-methyl-pent-2-enoic acid methyl ester