Convergent access to polycyclic cyclopentanoids from a,b-unsaturated acid chlorides and alkynes through a reductive coupling, Nazarov cyclization sequence

Reductive coupling of a,?-unsaturated acid chlorides A with alkynoyls B provides convergent access to Nazarov cyclization precursors, a-carboxy divinyl ketones C. Cyclization of C gives an intermediate oxyallyl cation intermediate D, which can be trapped with tethered arenes (Ar). The resultant products can be further cyclized through nucleophilic displacement of suitable leaving groups X by tethered OH groups to give lactones (in a subsequent step). Where X is a suitable chiral auxiliary (e.g., oxazolidinone) this strategy affords access to homochiral cyclopentanoids