Studies in iridoid synthesis. Chemoselective transformations of cis-1,2,4,6-tetrahydrophthalic anhydride
作者:Anne T. Stevens、James R. Bull、Kelly Chibale
DOI:10.1039/b716256a
日期:——
cis-1,2,4,6-tetrahydrophthalic anhydride was transformed into the corresponding lactone cis-3a,4,7,7a-tetrahydro-3H-isobenzofuran-1-one, which served as a key precursor for a variety of chemoselective synthetic manipulations. Unsuccessful formylation of an ester intermediate resulted in a (E/Z) mixture of vinyl alcohols which were protected as acetates and as a single p-methoxybenzyl (PMB) ether (E)
在关于开发非对映体至类拟南芥糖苷配基的合成研究过程中,将顺式1,2,4,6-四氢邻苯二甲酸酐转化为相应的内酯顺式-3a,4,7,7a-四氢-3H-异苯并呋喃1-one,用作各种化学选择性合成操作的关键前体。酯中间体的甲酰化失败,导致乙烯醇的(E / Z)混合物受到乙酸盐和单个对甲氧基苄基(PMB)醚(E)异构体的保护。使用OsO(4)的环己烯基序的二羟基化导致PMB醚的意外脱保护。另一方面,使用叔丁氧基双(二甲基氨基)甲烷或布雷德克氏试剂成功地将甲硅烷基保护的内酯化的中间体成功甲酰化。