New total synthesis of (+)-cystothiazole A based on palladium-catalyzed cyclization–methoxycarbonylation
作者:Keisuke Kato、Takamitsu Sasaki、Hiroyuki Takayama、Hiroyuki Akita
DOI:10.1016/s0040-4020(03)00300-4
日期:2003.4
3S)-epoxy butanoate 7 followed by methylation gave the tetrahydro-2-furylidene acetate (−)-10, which was converted to the left-half aldehyde (+)-3. A Wittig reaction between (+)-4 and the phosphoranylide derived from the bithiazole-type phosphonium iodide 4 using lithium bis(trimethylsilyl)amide afforded the (+)-cystothiazole A (2).
衍生自(2 R,3 S)-环氧丁酸酯7的(2 R,3 S)-3-甲基戊4炔-1,2-二醇(6)的钯催化环化-甲氧基羰基化,然后甲基化得到四氢乙酸-2-亚呋喃酯(-)- 10,其被转化为左半醛(+)- 3。使用双(三甲基甲硅烷基)氨基锂,(+)- 4与衍生自苄基唑型碘化4 4的磷酰内酯之间的维蒂希反应,得到(+)-巯基噻唑A(2)。