Abstract A rapid convergent strategy to access unsaturated analogues of peloruside A has been demonstrated. This is depicted as an original C11–C12 aldol connection between a C12–C20 ketone fragment and a C2–C11 pyran fragment bearing an aldehyde function, with high yield and a good level of diastereoselectivity. The desired unsaturated macrocycle was obtained by a late-stage ring closing metathesis reaction.
