Total synthesis of each enantiomer of falcarinol and panaxjapyne A via asymmetric catalytic alkynylation of an aldehyde

A concise and highly enantioselective (>99% ee) synthesis of falcarinol and panaxjapyne A and their enantiomers has been accomplished. The key steps involve the asymmetric addition of alkynylzinc reagent to acrolein and propionaldehyde catalyzed by a BINOL–Ti(OiPr)4 complex and a classic Cadiot–Chodkiewicz cross-coupling reaction. The chiral polyacetylenic alcohols synthesized herein have potential utility in the development of antitumor drugs and antidiabetic agents.

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(S,Z)-Heptadeca-1,9-diene-4,6-diyn-3-ol[(S)-falcarinol]C17H24OEe = >99%[α]D20 = +37.9 (c 1.0, CHCl3)Source of chirality: (R)-BINOLAbsolute configuration: (S)

(S,Z)-Heptadeca-9-ene-4,6-diyn-3-olC17H26OEe = >99%[α]D20 = +11.6 (c 1.0, CH3OH)Source of chirality: (R)-BINOLAbsolute configuration: (S)