RING-FUSED LACTAM DERIVATIVES WITH A DIEXOMETHYLENE MOIETY AND THEIR PREPARATION METHOD

摘要

A ring-fused lactam derivative with a diexomethylene moiety is provided to be very useful in medicine as well as precision chemistry industries and be useful as an intermediate for preparing an important multicyclic compound through the Diels-Alder reaction. And a method for preparing the same is provided to mass-produce the desired product industrially through a relatively simple process. A ring-fused lactam derivative with a diexomethylene moiety is represented by the formula(1), wherein R1 is H or C1-6 alkyl; each R2 and R3 is H, C1-6 alkyl or C1-6 alkoxy, or the R2 and R3 are bound to each other to form a pentagonal to a decagonal aliphatic or an aromatic hydrocarbon ring; and n is 0 or 1. A method for preparing the compound of the formula(1) comprises a step of subjecting hydroxy lactam including trimethylsilylmethyl-allene represented by the formula(2) to the intramolecular acyliminium cyclization in the presence of Lewis acid.