Donor-acceptor binary photocatalysis system illustrated by the intramolecular cyclization of a cyclopropanone acetal tethered to cyclohexen- 2-one

Article abstract of DOI:10.1246/bcsj.72.511

Irradiation of 2-[3-(2-methoxy-1-phenyl-2-TBDMSO-cyclopropyl)-propyl]- 2-cyclohexen-l-one (5) in the presence of Mg(ClO₄)₂ (1 mol equiv) and 9,10- dicyanoanthracene (DCA, 0.5 mol equiv) in acetonitrile formed methyl 5-oxo- 1-phenyldecahydro-l-naphthateneacetate (6) in 63% yield. When pyrene was adopted in place of DCA, the yield of 6 was 38%. The results indicate that the photocyclization of 5 induced by the SET can be catalyzed by both donor- and acceptor-type photocatalysts. Irradiation of a similar substrate, 4-(2- methoxy-1-phenyl-2-TBDMSO-cyclopropyl)butyl 2-naphthyl ketone (21), produced methyl 2-hydroxy-2-(2-naphthyl)-l-phenylcyclohexaneacetate (27) in 13% in the presence of p-dicyanobenzene (0.1 mol equiv) and 8% in its absence.