NEW MATERIAL:An optically active or inactive benzo-azabicyclo[3,3,1]-nonane derivative of formula I (R1 is monofunctional substitution group; n is 0, 1, 2; when n is 0, (R1)n- is H, and when n is 2, two R1s may together form a ring; C atom having × mark is asymmetric carbon).

EXAMPLE: d-9-Aza-9-methyl-benzo(f)-bicyclo[3,3,1]-non-6-en-3-one.

USE: Analgesic, antitussive, antihypertensive agent, anti-Perkinson's disease agent, and synthetic intermediate thereof.

PROCESS: The compound I is prepared by the Dickman reaction of an optically active or inactive ester of formula II (R2,3 are 1-4C alkyl), followed by heating with a mineral acid.