Reactions of Vinyloxyboranes. A Convenient Method for the Preparation of β-Hydroxy Thiolesters, Esters and Ketones

Abstract
It was found that the reaction of thioboronites with carbonyl compounds and ketene proceeds with the initial formation of vinyloxyboranes (VII). The boranes were found to be important intermediates for the formation of β-hydroxythiolesters by the reaction with various carbonyl compounds. Vinyloxyborane derivatives can be alternatively prepared by the reactions of trialkylboranes and α-diazocarbonyl compounds. The boranes similarly reacted with carbonyl compounds to give β-hydroxyketones and β-hydroxyesters.