PROCESS FOR PRODUCING POLYCYCLIC LACTAM

1. A method of producing lactams of the following formula (1) comprising the following three steps A to C: [when R 3 and R 4 are both a hydrogen atom, R represents a substituted methylene group or an optionally substituted polymethylene group, when at least one of R 3 and R 4 is a substituent other than a hydrogen atom, R represents an optionally substituted methylene group or an optionally substituted polymethylene group, R 3 , R 4 , R 5 and R 6 represent each independently a hydrogen atom, halogen atom, cyano group, optionally substituted alkyl group, optionally substituted alkenyl group, optionally substituted aryl group, optionally substituted amino group, -OR a group, -SR b group or - COOR c group.] (Step A) a step of reacting lactones of the following formula (2): and imides of any of the following formulae (3a), (3b) and (3c): [A 1 , A 2 , A 3 , A 4 , A 5 , A 6 , A 7 , A 8 , A 9 and A 10 represent each independently a hydrogen atom, halogen atom, nitro group, alkyl group, alkenyl group, optionally substituted aryl group, optionally substituted acyl group or -OR d .] to produce the correspondent carboxylic acids, (Step B) a step of esterifying the carboxylic acids to produce the correspondent esters, (Step C) a step of reacting the esters and amines to produce lactams of the formula (1).