Abstract The acetoxyaldehyde 9 prepared in five steps from methylcyclohexene 4 furnished the alkylidine succinic ester 12 when reacted with diethyl diethoxyphosphinylbutanedioate 11. The ester 12 was transformed to the half ester 17, which on oxidative decarboxylation (lead tetraacetate, cupric acetate) gave a 3: 1 mixture of esters 18 and 2 which was converted to the Queen Substance 1.
