44. Vitamin-B12-Catalyzed C,C-Bond Formation. Synthesis of a California Red Scale Phermone

Article abstract of DOI:10.1002/hlca.19930760205

A mixture of (3S,6R)- and (3R,6R)-3-methyl-6-(1-methylethenyl)dec-9-enyl acetate (1a and 1b, respectively) - 1a being a phermone of the California red scale - is synthesized in 14 steps from (+)-(R)-limonene (4).The key step is the reductive vitamin-B₁₂-catalyzed coupling of (R)-5-(2-iodoethyl)-6-methylhept-6-en-2-one ethylene acetal (8) and methyl crotonate (3).