Wittig reaction Peterson methylenation compared with

Peterson Alkenation. Trimethylsilylmethyllithium (1) provides an alternative to a Wittig approach for the preparation of methylene compounds from carbonyl precursors. In some cases the use of (1) is superior to the Wittig approach. Condensation of (1) with a carbonyl compound results in the formation of a 8-hydroxysilane. Elimination to the alkene can be acconqtlished by use of acidic or basic conditions (eq 1). acetyl chloride or thionyl chloride can also be used to accomplish this elimination. A wide variety of aldehydes and ketones have been used as substrates in this reaction. The use of cerium(III) chloride has been advocated with reagent (1) to favor nucleophilic addition with enolizable carbonyl corrqtounds. The use of the lithium agent (1) gives superior yields compared to the use of trimethylsilylmethyl-magnesium chloride with cerium, ... 

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