The alkaloid ester homoharringtonine (2) was synthesized stereospecifically via the Reformatsky reaction of methyl a-bromoacetate with cephalotaxyl pyruvate (16) obtained by esterification of cephalotaxine with acid chloride derived from 15. The preparations of 2 and ita unsaturated derivative 13 are described in detail. Possible explanations of the steric requirements in the esterification of cephalotaxine and of the steric outcome of the ...