The first convergent synthesis of methyl -butyldimethylsilyloxy-5(S),6
(S)-epoxy-icosa-7(E), 9(E), ll(Z), 14(Z)-tetraenoate (19(RS)-O-TBDMS-L
TA4 1) is described, using a Wittig reaction between a C1-C-11 chiral
epoxydienal (from (-)-2-deoxy-D-ribose as starting material) and an (o
mega - 1) functionalized phosphorus ylide, which was obtained by a rea
ction of alkyl bromide and lithium alkynylide. This strategy is suffic
iently general and could allow to synthesize other analogues giving ne
w haptens.