A NEW METHOD FOR REGIOSELECTIVE SYNTHESIS OF α-SUBSTITUTED ALLYLSILANES AND ITS APPLICATION TO THE SYNTHESIS OF E- AND Z-TAGETONES

摘要: Sequential addition of lithium salt carbanion and tributylstannylmethyl iodide (3) to vinyl sulfone 2 afforded β-tributylstannyl sulfones 5, which gave substituted allylsilanes 1 in a regioselective manner by the smooth destannylsulfonation. Allylsilane 8 prepared Michael type isopropenyllithium was converted into tagetones (10).