The synthesis of some novel chromans

Abstract

The inverse-electron demanded Diels-Alder reaction of 1-N,N-dimethylaminomethyl-2-naphthol (1) with substituted styrenes were investigated. With 2-, 3-, 4-methylstyrenes, 2-(2'-,3'- and 4'-methylphenyl)-benzo-5,6-chromans (5, 6 and 7) were obtained in 12, 18 and 53 % yields respectively. With 2-, 3- and 4-chlorostyrenes, 2-(2'-, 3'- and 4'-chlorophenyl)-benzo-5,6-chromans (8,9 and 10) were obtained in 8, 20 and 33 % yields respectively. With 4-vinyl-pyridine, 2-(4'-pyridyl)-benzo-5,6-chroman (11) was obtained in 48% yield. In all pyrolysis no quinone-methide dimer (4) was encountered.