Preparation of Keto Ethers of 5-Hydroxycyclooctanone via a Nonclassical Protection­ Method

Abstract

Protection of the hydroxy group of the medium-ring hydroxy ketone, 5-hydroxycyclooctanone (1HK), can be achieved with an alcohol and hydrochloric acid, although the substrate predominately exists as the transannular hemiacetal 1HA. The reaction is explained by a mechanism, which includes a 1,5-hydride shift as an essential step.

Key words

medium rings - transannular acetals - protection - trans­annular reaction - hydride shift

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