作者:Saengchai Wattanasereekul、Martin E. Maier
DOI:10.1002/adsc.200404004
日期:2004.6
depsipeptide jasplakinolide (1) was prepared in a sequence of 13 steps from the silylated 3-hydroxy ester 6. By chain extension 6 was converted to the allyl alcohol 10. A subsequent asymmetric cyclopropanation of the allylic alcohol 10 using the Charette method provided the hydroxymethylcyclopropane 12 with excellent diastereoselectivity. This cyclopropanation was used to establish the methyl-bearing
从甲硅烷基化的3-羟基酯6按13个步骤的顺序,制备了二十肽萘普普利特(1)中所含的受保护的ω-羟基酸4b。通过扩链6将其转化为烯丙醇10。随后使用Charette方法进行的烯丙基醇10的不对称环丙烷化为羟甲基环丙烷12提供了优异的非对映选择性。该环丙烷化用于通过(碘甲基)环丙烷14的还原环裂解在羟基酸4的C-6处建立含甲基的立体中心。烯烃15将其用于与2-甲基丙烯酸酯20的交叉烯烃复分解反应,提供烯酸酯19。所得的烯丙基碘化物24在最终的Evans烷基化步骤中用作亲电子试剂,得到ω-羟基酸衍生物26。