Patent ID: 6951964

Claim:
A method for producing macrocyclic ketones of the formula Ia; or Ib wherein R 1 , R 2 , and R 3 are independently hydrogen, or a C 1 to C 6 alkyl group; or R 1 , R 2 , and R 3 are independently hydrogen, or a C 1 to C 6 alkyl group, and R 1 and R 2 or R 2 and R 3 form together with the carbon atom(s) to which they are attached a ring; R 4 is hydrogen, a linear or branched C 1 to C 4 alkyl group; and n is an integer of 7 to 14; comprising the steps: (a) converting to 100° C.-300° C. into the gas phase a compound of formula IIa or formula IIb wherein R 1 , R 2 , R 3 , R 4 , and n have the same meanings as above; and R 5 is either hydrogen or a trialkylsilyl group or an alkali metal cation; and (b) heating the compound of formula IIa or formula IIb, converted into the gas phase under (a), to temperatures of from 500° C. to 700° C., and (c) if R 5 is a trialkylsilyl group, hydrolysis of the trialkylsilyl ether resulting under (b) into the corresponding ketone of the formula Ia or Ib.