Diastereoselective Synthesis of Eight‐Membered‐Ring Allenes from Propargylic Epoxides and Aldehydes by Silylene Insertion into Carbon–Oxygen Bonds

Abstract

Bent out of shape: Silver-catalyzed insertions of silylenes into propargylic CO bonds of epoxides regioselectively form 1,2-silaoxetanes, which add to aldehydes to give the title allenes as single diastereomers (see scheme; Ts=4-toluenesulfonyl). An X-ray crystal structure confirmed the stereochemistry of the allene, which is bent significantly from linearity (164°).