Didier Michelot

Reaction of dimethylvinylidene with γγ-dimethylallyl methyl sulphide. Synthesis of 2,5,5-trimethylhepta-2,6-dien-4-one (artemisia ketone)

The [2,3] sigmatropic rearrangement of the sulphonium ylide derived from the title reaction, followed by hydrolysis of the allenic thioether product affords artemisia ketone (6).

Allenyllithium Reagents (VI)1. A Highly Regioselective Metalation of Allenic Hydrocarbons2. A Route to Mono, DI, TRI or Tetrasubstituted Allenes

Abstract The monometalation of allenic hydrocarbons has received little attention5. The formation of 1,2-propadienyllithium was described by treatment of 1,2-propadiene with n-butyllithium in tetrahydrofuran-hexane6. The structure of the organometallics was proved by I.R. spectroscopy. However, reaction with benzophenone gave a pure propargylalcohol and silylation gave a mixture of allenylsilane and propargylsilane.

A Convenient Preparation of Benzylic Homopropargylic Alcohols Via Allenyllithium Reagents

Abstract Among the distinctive methods providing acetylenic functions1-3 reactions employing anionic propargylic equivalents opposed to electrophilic species provide a potentially valuable route to propargylic derivatives4-6. Their general applicability in synthetic processes, however, is frequently hampered by the tendency of such nucleophiles to produce troublesome mixtures of isomeric acetylenic and allenic products in moderate yields.

Simple route to mono-, di-, and tri-substituted allenic compounds

Allenic compounds can be prepared in high yields without appreciable rearrangement by alkylation of allenic lithium reagents.