[GRAPHICS]Palladium-catalyzed hydrostannation of substituted Z- and E-enynols is discussed and compared. The regioselectivity of the H-Sn bond addition was found to be controlled by the geometry of the double bond ( Z- or syn-directing effect) rather than the nature of its substituents. Exclusively alpha-vinyl stannanes were obtained from Z-enynols having various substituents on the double bond regardless of their electronic, steric, or chelating natures.
A stereoselective synthesis of ω-chlorodienals and ω-chlorodienones was described. Conjugated ω-chlorotrienals and trienones were also easily prepared via an efficient palladium-catalyzed rearrangement of allylic acetates.