Carbohydrate Carbocyclization by a Zinc-Mediated Tandem Reaction and Ring-Closing Enyne Metathesis
作者:Carina Storm Poulsen、Robert Madsen
DOI:10.1021/jo0200062
日期:2002.6.1
Methyl 5-deoxy-5-iodo-pentofuranosides are reductively ring-opened and propargylated in a tandem fashion in the presence of zinc. The 1,7-enynes thus obtained are subjected to ring-closing enyne metathesis with catalyst B to produce functionalized 1-vinyl cyclohexenes. By adding BnNH(2) to the tandem reaction, an amino group can be introduced in the 1,7-enyne products. Addition of 2-TMS-ethynylcerium(III)
在锌的存在下,将5-脱氧-5-碘-戊呋喃糖苷甲基以串联方式还原性地开环和炔丙基化。将由此获得的1,7-烯炔与催化剂B进行闭环烯炔复分解,以产生官能化的1-乙烯基环己烯。通过将BnNH(2)添加到串联反应中,可以在1,7-烯炔产品中引入氨基。在还原性开环后加入2-TMS-乙炔基氯化铈(III)产生相应的1,6-烯炔。通过良好的立体化学控制的Diels-Alder反应,可以实现产物1,3-二烯的进一步环化。这些程序构成了用于碳水化合物的快速碳环化和环化以产生各种功能化的五元和六元环系统的有效方法。