Thionyl chloride, DMSO activator

A novel synthetic approach was developed by R.E. Taylor et al. for the preparation of the triene portion of the biologically active polyketide apoptolidin. The allylic chloride substrate was prepared from an allylic alcohol via a thionyl chloride mediated rearrangement. Next, the allylic chloride was subjected to the Ganem oxidation by treating it with five equivalents of trimethylamine A/-oxide (TMANO) in DMSO at room temperature to obtain the desired a,p-unsaturated aldehyde. Interestingly, the original Kornblum oxidation conditions were not well suited for this system because of the required high reaction temperature. 

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