Novel heterocycles derived from 3‐acyloxy‐ and 3‐acetamidoquinuclidines

Abstract New quinuclidine derivatives with 3‐spiro annelated oxathioline, furanone, and pyrrolinone heterocycles have been synthesized from 3‐mesyloxy‐, 3‐acetoxy‐, and 3‐acetamidoquinuclidine‐3‐carbonitrile, respectively, by treatment with base. Treatment of 3‐acetamidoquinuclidine‐3‐carbonitrile (3) with potassium hydride resulted in decyanation whereas alkyllithium reagents attacked the cyano group in 3 to produce the corresponding imines. Oxidative cyclization of the N‐benzylated derivative of 3 with palladium acetate gave the tetracyclic compound 5‐acetyl‐1,4‐ethano‐1,2,3,4,5,6‐hexahydrobenzo[c]‐1,5‐naphthyridine.