Methyl exchange on silicon during the addition of methylmagnesium iodide to a cyanohydrin O-silyl ether

Abstract

Reaction of [¹³C]methylmagnesium iodide (99 atom% ¹³C) with cyanohydrin O-trimethylsilyl ether 1, followed by acidic hydrolysis, led to the formation of a methyl ketone derivative 2a that was only partially labelled (60 ± 5 atom% ¹³C); this loss of labelling occurred through a methyl exchange reaction on silicon as shown by the presence on intermediate 2b of [¹³C]methyl groups on silicon (30 atom% ¹³C).