作者:Hiroyuki Akita、Noriyuki Sutou、Takamitsu Sasaki、Keisuke Kato
DOI:10.1016/j.tet.2006.09.064
日期:2006.12
3S)-epoxy butanoate 5 gave the acetylenic ester 10, which was treated with MeOH in the presence of Bu3P to afford selectively (Z)-β-methoxy acrylate congener 11 in 86% yield. Treatment of (Z)-11 with 99.8% enrichment of CDCl3 followed by consecutive desilylation and oxidation afforded the left-half aldehyde (+)-2. The overall yield (10 steps from 5; 23%) of (+)-2 via the present route was improved in comparison
( - ) - (2-的钯催化的甲氧基羰基- [R,3小号)-1-叔-butyldimethylsiloxy -3-甲基-2- methoxypenta -4-炔9衍生自(2 - [R,3小号) -环氧丁酸酯5,得到炔酸酯10,在Bu 3 P存在下用MeOH处理,以86%的收率选择性提供(Z)-β-甲氧基丙烯酸酯同类物11。用99.8%的CDCl 3富集处理(Z)-11,然后连续进行甲硅烷基化和氧化,得到左半醛(+)- 2。总产率(从10个步骤5 ; 23%) -的(+)2经由本路线被相较于(从10步提高5 ;先前报道的路线的10%)。通过将修改Julia的联接方法,选择性(Ë / ž = 14:1)的(ë) -形式(cystothiazole阿1)抵靠(Ž)构型在相比于维悌希方法改善(Ë / ž = 4:1至6.9:1)。