The Journal of Organic Chemistry

Neighboring group participation in Lewis acid-promoted [3+ 4] and [3+ 5] annulations. The stereocontrolled synthesis of tricyclic ethers

GA Molander, KO Cameron

Index: Molander, Gary A.; Cameron, Kimberly O. Journal of Organic Chemistry, 1993 , vol. 58, # 22 p. 5931 - 5943

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Citation Number: 47

Abstract

A variety of 1, 4-and 1, Bketo aldehydes derived from cycloalkanes are coupled with the bis (trimethylsily1) enol ether of methyl acetoacetate in the presence of either TMSOTf or TrSbCk to generate tricyclic ethers. The reactions proceed with excellent regiochemical control by a mechanism involving neighboring group participation. This mechanism involves initial formation of a bicyclic oxocarbenium ion intermediate from the keto aldehyde ...