Thiophene Derivatives by Novel Rearrangements of Siloxy‐substituted Cyclopropanecarboxylates

Abstract

The ester enolate of the siloxycyclopropanecarboxylate 1 reacts with CS2 and methyl iodide to give a ring-expanded dihydrothiophene derivative, which, via Lewis acid-induced shifting of an alkyl group, gives the thiophene 2. The reaction can be extended to analogues of 1; the OSi(CH3)3 group, however, is indispensable.