Reaction of dichlorocarbene with substituted 3,4-dihydroisoquinolines and 1-methylene-1,2,3,4-tetrahydroisoquinolines

Reaction of dichlorocarbene with 3,3-dialkyl-3,4-dihydroisoquinolines results in the formation of gemdichloroazirino2,1-a]isoquinolines, which are in turn converted to 3-benzazepinones upon hydrolysis. Reaction of dichlorocarbene with the ethyl ester or amide of (3,3-dimethyl-1,2,3,4-tetrahydroisoquinolin-1-ylidene)acetic acid is accompanied by rearrangement of the intermediate carbene adducts at the enamine C=C bond and results in the formation of a 1-azadiene, 3-(3,3-dimethyl-3,4-dihydroisoquinolin-1-yl)-3-chloroacrylic acid ethyl ester, and a spirolactam, 3,3-dimethyl-3-chlorospiro1,2,3,4-tetrahydroisoquinoline-1,2-pyrrole]-5(2H)-one, respectively.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1086–1091, August, 1990.