Total synthesis of (−)-dihydroprotolichesterenic acid via diastereoselective conjugate addition to a chiral fumarate

A diastereoselective conjugate addition of a variety of monoorganocuprates, Li[RCuI], to chiral fumarates to provide funtionalized succinates has been developed. The utility of this reaction is demonstrated in a concise total synthesis of (−)-dihydroprotolichesterenic acid that required only four steps and proceeded in an overall 31% yield.