The alkylation by allyl halides of the intermediate enolate, prepared in situ by conjugate addition of di-p-tolylcuprate to chiral (p-tolylsulfinyl)pyrrolyl cinnamoyl amide, gave the (2R,3R)-adducts as the major products with 81% to 94% de’s. Methanolysis of the products afforded the corresponding methyl esters, together with efficient recovery of the chiral sulfinyl auxiliary without loss of optical purity.
通过将二
对甲苯基杯酸盐与手性(
对甲苯基亚磺酰基)
吡咯烷肉桂酰酰胺共轭加成法原位制备中间体烯酸盐,烯丙基卤化物对中间体烯酸盐进行烷基化反应,得到 (2R,3R)-加合物作为主要产物,de's 为 81% 至 94%。对这些产物进行
甲醇分解可得到相应的甲酯,同时还能有效地回收手性亚磺酰基助剂,而不会损失光学纯度。