Patent ID: 8563781

Claim:
A process for preparing ketones of the formula II, wherein A is a C 2 -C 12 -alkanediyl which is optionally substituted by from 1 to 5 C 1 -C 6 -alkyl groups, R 1 and R 2 are each, independently of one another, C 1 -C 6 -alkyl or R 1 and R 2 together form C 3 -C 10 -alkanediyl which is optionally substituted by from 1 to 5 C 1 -C 6 -alkyl groups, and R 3 is hydrogen or a C 1 -C 6 -alkyl; said process comprising: (a) reacting a cyclic olefin of the formula I with dinitrogen monoxide to give the ketone of the formula II.