Stereoselective Synthesis of Alcohols, XLII. Stereoselective Cyclization of (8‐Oxo‐2‐octenyl)boronates to <i>cis</i>‐ or <i>trans</i>‐2‐Vinylcyclohexanol

Abstract

Abstract Intramolecular allylboration reactions of (8‐oxo‐2‐octenyl)boronates proceed with excellent diastereoselectivity: the E ‐isomer 1d leads to the trans ‐2‐vinylcyclohexanol ( 2 ) with 99.5% d.s., the corresponding Z‐isomer 3d cyclizes to give the cis ‐isomer with a diastereoselectivity exceeding 99.8%.