Carbohydrate Carbocyclization by a Novel Zinc-Mediated Domino Reaction and Ring-Closing Olefin Metathesis
作者:Lene Hyldtoft、Robert Madsen
DOI:10.1021/ja001415n
日期:2000.9.1
is described using two consecutive organometallic transformations: a novel zinc-mediated domino reaction to give functionalized dienes followed by ring-closing olefin metathesis. In the first reaction, methyl ω-deoxy-ω-iodo glycosides undergo reductive elimination with zinc to produce a terminal double bond. This also liberates the aldehyde which is immediately alkylated in situ by various organozinc
使用两个连续的有机金属转化描述了碳水化合物碳环化的一般方法:一种新型的锌介导的多米诺反应,产生官能化的二烯,然后是闭环烯烃复分解。在第一个反应中,甲基ω-脱氧-ω-碘糖苷与锌进行还原消除以产生末端双键。这也释放出醛,该醛立即被各种有机锌试剂原位烷基化。在巴比耶条件下,用亚甲基碘和几种烯丙基溴进行烷基化。锌通过促进还原消除和激活烷基卤而发挥双重作用。通过添加二乙烯基锌进行乙烯基化。当产生一个新的立体中心时,一般会观察到中等至极好的立体控制。氨基可以通过在烷基化之前将中间体醛捕获为亚胺来引入。铟金属也可以促进还原消除-烯丙基化序列。所有的...