Isomerization of Allylic Alcohols Catalyzed by Vanadium or Molybdenum Complexes

Abstract Isomerization of primary allylic alcohols proceeds in dichloromethane at 25 °C in the presence of the catalyst prepared in situ from VO(acac)2 or MoO2(acac)2, and Me3SiOOSiMe3 to give tertiary isomers in good yields. The catalysts are also effective for the rearrangements of sec.→tert. allylic alcohols. The isomerization of an allenyl allylic alcohol, 6-methyl-1,2,5-heptatrien-4-ol, gives either (E)-2-methyl-3,5,6-heptatrien-2-ol or (E)-6-methyl-3,5-heptadien-2-one selectively depending on the reaction conditions.