Hydrogen-bonding directed, regioselective photocycloaddition reactions of cyanonaphthalenes with furanmethanols.

1-Cyanonaphthalene and 2-cyanonaphthalene react with 2-furanmethanol and 3-furanmethanol, respectively, under photoirradiation conditions to give [4 + 4] photocycloadducts and caged compounds with high degrees of regioselectivity. Analysis of data obtained from variable temperature (1)H NMR and fluorescence quenching experiments indicates that hydrogen bonding between cyano and hydroxy groups in the excited states of the corresponding naphthalene and furanmethanol substrates is the source of the observed regioselectivities.