TOTAL SYNTHESIS OF LEUKOTRIENE-B(4)

A new, efficient, and stereocontrolled total synthesis of leukotriene B4 (1) has been developed. The convergent route employs a stereospecific Horner-Wadsworth-Emmons coupling of propargylic phosphonate 2 and aldehyde 3 to provide the essential carbon framework in 77% yield. The requisite phosphonate 2 containing the C1-C8 fragment was readily prepared in 47% yield from methyl 4-(chloroformyl)butyrate via an enantioselective reduction of alcohol 4 while the chiral aldehyde 3 which comprises the C9-C20 skeleton of the eicosanoid was synthesized in 52% yield from optically active (2R)-(-)-glycidyl 4-nitrobenzoate.