Photoinduced double [2 + 2] cycloaddition relay of yne–allenones for highly diastereoselective synthesis of hexacyclic 1-naphthols†
Abstract
A new photoinduced photocatalyst-free energy-transfer strategy for double [2 + 2] cycloaddition relay of yne–allenones is reported for the first time and used to produce a series of hitherto unreported hexacyclic 1-naphthols with good yields and complete diastereoselectivity. The reaction pathway generates a class of complex three-dimensional structures with two all-carbon quaternary centers evolved from the planar conjugated system through cleavage and recombination of the C–C triple bond of yne–allenones, enabling the direct formation of four new rings in one step.