Facile synthesis and bridgehead-functionalization of bicyclo[3.3.3]pentasiloxanes†
Abstract
A fascinating but still rare bicyclic siloxane, bicyclo[3.3.3]pentasiloxane, was synthesized by the oxidation of a bicyclic silicon cluster and characterized using a combination of NMR spectroscopy and X-ray diffraction analysis. The bridgehead OSiMe3 groups of the siloxane were selectively and efficiently converted to O−K+ (siloxide) by treating with tBuOK in the presence of 18-crown-6-ether. The resulting siloxides provided various bridgehead-functionalized bicyclo[3.3.3]pentasiloxanes after treatment with electrophiles.