A synthesis of the acid moiety of the insecticide Permethrin (NRDC 143)(1) starting from readily available 2-methyl-C-buten-2-01 (6) is described. Addition of carbon tetrachloride to 6 and subsequent treatment with base gave epoxide 8, which with dimethyl malonate formed the lactone 10. Decarboxylation and lactone opening with thionyl chloride and ethanol gave chloroester 15, which could be cyclized with strong base to the title ...
