The Metal-Ammonia Reduction of Mono- and Dinaphtylbenzenes

Article abstract of DOI:10.1021/jo00299a023

The metal-ammonia reduction of 1- and 2-phenylnaphthalene (9 and 10, respectively), 1,3-bis(1-naphthyl)benzene (5), 1,3-bis(2-naphthyl)benzene (6), 1,4-bis(1-naphthyl)benzene (7), and m-quinquephenyl (8) has been investigated. 9 affords a mixture of isomeric dihydro products together with 1-phenyl-1,2,3,4-tetrahydronaphthalene, and the effect of metal, temperature, and quenching methods on the product distribution is reported. 10 provided only a single dihydro (1,4-)isomer plus a tetrahydro product. both 5 and 7 provided a number of dihydro, tetrahydro, hexahydro, and octahydro products.On the other hand, 6 afforded high yields of a single tetrahydro product with lithium, and exclusively an octahydro product when 5-7 mol of sodium was used.In contrast to the terphenyls, which seem to have a propensity for inner-ring reduction, none of the naphthyl benzenes showed any tendency to reduce in the central benzene ring. m-Quinquephenyl reduced in two rings with no evidence for reduction in the central or outer rings.