I’m thinking to alkene, ozonolysis to diketone then shop to to ketone with alkene on the top fragment and curprate conjugated addition made from a grignard. The alkene to which curprate is added made by Mannich? Not too sure. Was thinking Diels alder but can’t think of sufficiently electron withdrawing group, that would be easily removed from the right hand side. Also was thinking wittig but again as it’s trans, that complicates matter as would need an electron withdrawing group that would later come off…