The prenyl group: a versatile hydroxy protecting group, removable chemoselectively under mild conditions
作者:Jean-Michel Vatèle
DOI:10.1016/s0040-4020(02)00539-2
日期:2002.7
6-dicyanoquinone (DDQ) in dichloromethane–water (9:1) are mild and efficient methods to cleave prenyl ethers. These reaction conditions are compatible with the presence of other protecting groups such as acetals, acetates, allyl, benzyl and TBDPS groups. Exposure of aryl prenyl ethers to iodine led to the formation of 3-iodo-2,2-dimethylchroman derivatives in acceptable yields via a tandem Friedel–Crafts/iodocyclization
二氯甲烷中的碘(在对酸敏感的底物存在3Å分子筛的情况下)和二氯甲烷-水(9:1)中的2,3-二氯-5,6-二氰基醌(DDQ)是裂解异戊二烯的温和有效方法醚。这些反应条件与其他保护基如缩醛,乙酸酯,烯丙基,苄基和TBDPS基团的存在相容。芳基异戊烯基醚暴露于碘导致通过串联的Friedel-Crafts /碘环化反应以可接受的收率形成3-碘-2,2-二甲基苯并二氢吡喃衍生物。两种碘化二甲基苯并二氢吡喃衍生物的简单一步转化就可以合成其中的天然黄酮类化合物:抗氧化剂花椒酚。