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Catalytic enantioselective Cr-mediated propargylation: application to halichondrin synthesis.

ABSTRACT: A catalytic enantioselective propargylation in the presence of 10 mol % of Cr catalyst prepared from Cr(III) bromide and (R)-sulfonamide E furnishes homopropargyl alcohol 8 in 78% yield with 90% ee. Coupled with the workup based on Amano-lipase, this method provides a practical synthesis of optically pure 8 on a multigram scale. With maintenance of its optical purity, 8 has been converted to 1b, the C14-C19 building block of halichondrins and E7389, in two steps.

SUBMITTER: Liu S

PROVIDER: S-EPMC2760007 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature

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Catalytic enantioselective Cr-mediated propargylation: application to halichondrin synthesis.

Liu Songbai S Kim Joseph T JT Dong Cheng-Guo CG Kishi Yoshito Y

Organic letters 20091001 20

A catalytic enantioselective propargylation in the presence of 10 mol % of Cr catalyst prepared from Cr(III) bromide and (R)-sulfonamide E furnishes homopropargyl alcohol 8 in 78% yield with 90% ee. Coupled with the workup based on Amano-lipase, this method provides a practical synthesis of optically pure 8 on a multigram scale. With maintenance of its optical purity, 8 has been converted to 1b, the C14-C19 building block of halichondrins and E7389, in two steps. ...[more]

PMID: 19810761

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