A Convenient Triisobutylaluminium (TIBAL)-Promoted Johnson-Claisen Approach to γ,δ-Unsaturated Alcohols
Kelly L. Cosgrove, Ross P. McGeary*
*School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia, Email: r.mcgearyuq.edu.au
K. L. Cosgrove, R. P. McGeary, Synlett, 2009, 1749-1752.
Mixed ortho esters derived from allylic alcohols undergo methanol elimination in the presence of triisobutylaluminium (TIBAL) at room temperature to form mixed ketene acetals. TIBAL then promotes immediate Claisen rearrangement of and a subsequent reduction of the ester products in the presence of DIBAL, to give unsaturated γ,δ-primary alcohols in a convenient, one-pot procedure.
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proposed reaction pathway
K. L. Cosgrove, R. P. McGeary, Synlett, 2008, 2425-2428.