Stereoselective reduction of α'-branched α,β-ynones. Application to the synthesis of the octalactin A ring

Article abstract of DOI:10.1016/S0040-4039(98)01420-8

A flexible, efficient route to chiral 3-hydroxy-4-methyl- and 3-hydroxy- 4-methoxyalkanoic acids, with high control of the C(3) configuration, has been disclosed, which is based on the borane-mediated reduction of 1- trimethylsilyl-1-alkyn-3-ones (6) in the presence of oxazaborolidine 7 followed by hydroboration of the resulting propargylic alcohols 4 and 5. This strategy has been applied to the synthesis of the Octalactin A ring.