A TBAF-mediated Chemoselective Method for Synthesis of 4-Methylbutenolides and 4-Hydroxy-4-methylbutenoIides from 3-Hydroxy-4-(tert-butyldimethylsiIyloxy)pentanoates

摘要

A chemoselective synthesis of butenolides was found based on TBAF-mediated deprotection, cyclization, dehydration, and oxidation of 3-hydroxy-4-(trert-butyldimethylsilyloxy)-pentanoates, which yielded either 4-methylbutenolides or 4-hydroxy-4-methylbutenolides in moderate to good yields. The selectivity depends on the quantity of TBAF. This method was applied to the synthesis of several 4-butenolide compounds.