The sequential Sonogashira cross-coupling reactions with water soluble
and anhydrous Pd(0) catalysts between vinylic iodo derivatives 6, 8 a
nd 3-iodocyclohexenone 7 with trimethyl silyl acetylene are used to pr
oduce functionalized intermediates 11 and 18. Conjugate addition follo
wed by enolate trapping with trimethyl orthoformate provided B-seco ta
xane derivatives 14 and 20.