Preparation and use of enantioenriched allenylsilanes for the stereoselective synthesis of homopropargylic ethers.

A convenient procedure for the synthesis of highly enantioenriched allenylsilanes by Johnson orthoester Claisen rearrangement of 1-silyl propargylic alcohols is described. Allenylsilanes are then used as carbon nucleophiles in three-component, Lewis acid mediated additions to in situ generated oxonium ions, resulting in enantioenriched homopropargylic ethers.