THE SYNTHESIS OF D(6)-ALPHA-FARNESENE

d(6)-alpha-Famesene methyl-12,12,12-H-2(3)-dodeca-1,3E,6E,10-tetraene) has been synthesised by two routes. Thermolysis of 2-geranyl-3-methyl sulpholene (5) yielded unlabelled alpha-famesene (93%) which was epoxi dized at Delta 10 in 31% yield. Oxidative cleavage of the epoxide (42% ) and Wittig elaboration of the resultant trienal with d(6)-Isopropyl triphenylphosphorane gave d(6)-alpha-famesene (73%). Alternatively, se lective epoxidation of (5) gave the terminal 6',7' mono-epoxide in 74% yield. Oxidative cleavage (73%) and Wittig elaboration of the resulta nt aldehyde;yielded deuterated 2-geranyl-3-methylsulpholene (46%). The rmal elimination of sulphur dioxide afforded the title compound in 91% yield.