β-Lithiooxyphosphonium ylides, generated in situ from aldehydes and Wittig reagents, react readily with halomethyl esters to form trisubstituted Z-allylic esters. The methodology was applied to a total synthesis of the geranylgeraniol-derived diterpene (6 S, 7 R, Z)-7-hydroxy- 2-((E)-6-hydroxy-4-methylhex-4-enylidene)-6, 10-dimethylundec-9-enyl acetate (12).
