Enantioselective Synthesis of cis-2,6-Disubstituted-4-methylene Tetrahy-dropyrans via Chromium Catalysis

• 作者: Jing Bai Bin Chen Guozhu Zhang
• 来源期刊: 中国化学（英文版）
• 年，卷（期）: 2020,（12）
• 所属期刊栏目: Concise Reports
• 页码范围: 1642-1646
• 页数: 5页
• 语种: 英文
• DOI: 10.1002/cjoc.202000296

摘要

Enantioenriched 2,6-disubstituted 4-methylene tetrahydropyrans have been obtained via a two-step sequence consisting of a highly enantioselective chromium-catalyzed carbonyl 2-(trimethylsilyl methyl)allylation and Prins cyclization.Commercially available(2-(chloromethyl)allyl)trimethylsilane serves as the bifunctional linchpin to combine two aldehydes to assemble the 2,6-disubstituted pyrans.A variety of functional groups are compatible under the mild reaction conditions.The synthetic utility of this methodology was demonstrated by the asymmetric synthesis of 16 examples of homoallylic alcohol and 8 examples of 2,6-disubstituted 4-methylene tetrahydropyrans,including an advanced intermediate which could be transformed to natural product centrolobine via a known procedure.