Functicnalization of 4-Hydroxy-6-Methyl-2-Pyrone at C-5 Through [2,3] Sigmatropic Rearrangements of Allylic Sulphonium Ylides

Abstract

Functionalization at C-5 of the triacetic acid lactone methyl ether, 7, has been achieved by a transfer from the C-6 position. Thus, treatment of sulfides 12 with an excess of ethyl diazoaceta-te provides the pyrones 15 through [2,3] sigmatropic rearrangements.