American Chemical Society
ol300852v_si_001.pdf (3.54 MB)

Palladium-Catalyzed Synthesis of 4-Oxaspiro[2.4]heptanes via Central Attack of Oxygen Nucleophiles to π-Allylpalladium Intermediates

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journal contribution
posted on 2012-05-04, 00:00 authored by Ryo Shintani, Tomoaki Ito, Tamio Hayashi
A palladium-catalyzed decarboxylative cyclopropanation of γ-methylidene-δ-valerolactones with aromatic aldehydes has been developed to give 4-oxaspiro[2.4]heptanes with high selectivity. The site of nucleophilic attack to a π-allylpalladium intermediate has been controlled with a sterically demanding phosphine ligand. The course of the reaction is highly dependent on ligands and solvents, and selective formation of methylenetetrahydropyrans has also been realized.