A Highly Efficient Synthetic Protocol for Tetrahydropyranylation/Depyranylation of Alcohols and Phenols
作者:Abu T. Khan、Subrata Ghosh、Lokman H. Choudhury
DOI:10.1002/ejoc.200500400
日期:2005.11
Bismuth(III) nitrate pentahydrate [Bi(NO3)3·5H2O] is found to be an effective catalyst for both tetrahydropyranylation and depyranylation of alcohols and phenols. Some of the major advantages of this protocol are: non-aqueous workup, good yields, the involvement of a less-expensive and nontoxic catalyst, and compatibility in the presence of a large number of other protecting groups. Notably, isopropylidene
五水合硝酸铋 (III) [Bi(NO3)3·5H2O] 被发现是醇和酚的四氢吡喃化和去吡喃化的有效催化剂。该协议的一些主要优点是:非水后处理、良好的收率、价格较低且无毒的催化剂的参与,以及在存在大量其他保护基团的情况下的兼容性。值得注意的是,异丙叉、亚苄基和硫代缩醛基团在实验条件下也不受影响。值得注意的是,通过使用相同的催化剂,可以化学选择性地实现二醇和伯醇的选择性单保护。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)