Conversion of bicyclic αα-dichlorocyclobutanones into monocyclic β-formyl esters and bicyclic cyclopropanes with silver tetrafluoroborate

Abstract

Bicyclic αα-dichlorocyclobutanes (1) and (2)(R = H), treated with silver tetrafluoroborate in aqueous alcoholic solution, gave bicyclic α-chlorocyclopropanecarboxylic acids and esters (3) and (6) together with monocyclic β-formyl esters (4), (5), and (7)(R = H). The alkoxy-derivatives of (1) and (2)(R = alkoxy), however, gave only the β-formyl esters (4), (5), and (7)(R = alkoxy).