Tetrahedron Letters

Regiospecific α-methylenation and α-methylation of ketones: titanium tetrachloride promoted phenylthiomethylation of silyl enol ethers

I Peterson, I Fleming

Index: Paterson,I.; Fleming,I. Tetrahedron Letters, 1979 , # 11 p. 995 - 998

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Citation Number: 25

Abstract

Existing synthetic methods for a-methylenation of ketones have, in general, been based on alkylation by formaldehyde3 or Mannich reagents 5, 6 followed in one or two steps by E- elimination. These methods suffer from the disadvantages that: they are not regiospecific with unsymmetrical ketones, unless a kinetically generated specific enolate is available; the S-hydroxy and S-aminoketones are sensitive intermediates; and the necessary ...