Biosynthesis-Inspired Intramolecular Oxa-Conjugate Cyclization of α,β-Unsaturated Thioesters: Stereoselective Synthesis of 2,6-<i>cis</i>-Substituted Tetrahydropyrans
作者:Haruhiko Fuwa、Kenkichi Noto、Makoto Sasaki
DOI:10.1021/ol200333p
日期:2011.4.1
Intramolecular oxa-conjugate cyclization of alpha,beta-unsaturated thioesters under Bronsted acid catalysis, inspired by biosynthesis of polyketide natural products, provides a variety of 2,6-cis-substituted tetrahydropyran derivatives with excellent diastereoselectivities. An added bonus of this methodology is that the product tetrahydropyrans could be readily elaborated to various derivatives by exploiting the unique reactivity of the thioester group.
Stereoselective Synthesis of 2,6-<i>Cis</i>-Substituted Tetrahydropyrans: Brønsted Acid-Catalyzed Intramolecular Oxa-Conjugate Cyclization of α,β-Unsaturated Ester Surrogates
for the synthesis of tetrahydropyrans. However, it has been known that stereochemical outcome of IOCC depends on the local structure of substrates and sometimes requires harsh reaction conditions and/or prolonged reaction times for selective formation of 2,6-cis-substituted tetrahydropyrans. These shortcomings limit the feasibility of IOCC in the context of complex natural product synthesis. In this