Synthesis of Furoquinolines

Abstract

Furoquinolines, viz., kokusagine (I), maculine (II), dictamnine (III) and 6-methoxy-dictamine (IV) were synthesized via ethyl 2-anilino-4, 5-dihydro-4-oxofuran-3-carboxylate derivatives. 6-Methoxy-2-methyldictaminne (V) and its dihydro-derivative (XXI) were synthesized via analogous ethyl 4, 5-dihydro-2-(4-methoxyanilino)-5-methyl-4-oxofuran-3-carboxylate. Stereochemical assignments of 2, 3-cis and trans 2, 3-dihydro-3-hydroxy-4, 6-dimethoxy-2-methylfuro[2, 3-b]quinoline having insect antifeeding activity were made on the basis of their spectrometric data (PMR and MS).