An optically active juvenile hormone analogue,S-(+)-methoprene (1), is synthesized in six steps from technical gradeS-(+)-3,7-dimethyl-1,6-octadiene (“(+)-dihydromyrcene”, e.e. −50%) by a novel procedure which begins with selective hydroalumination-oxidation to giveS-(-)-citronellol. This alcohol is oxidized to giveS-(-)-citronellal which on reaction with allylmagnesium chloride affords 6S, 10-dimethyl-1,9-undecadien-4 R/S-ol (5). Smidt-Moiseev oxygenation of 5 followed by dehydration leads to 6S, 10-dimethyl-3E,9-undecadien-2-one. The latter on treatment with isopropoxyethynylmagnesium bromide is transformed into isopropyl 3,7S,11-trimethyl-2E/Z,4,E,10-dodecatrienoate which upon Brown solvomercurationreduction in MeOH gives1 in 14% overall yield.