Three unsaturated vinylic or allylichalides were made in enantiomerically pure form, ready for coupling with a vinyl metal as part of a divergent strategy for the synthesis of members of the domoic/isodomoic acid family and their analogues. The trisubstituted alkene 3 was made by an E-selective Wittig reaction, while 4 and 5 were made by stereoselective hydrometallation or hydroboration of an alkyne