Patent ID: 8664450

Claim:
A process for the manufacture of gamma-delta-unsaturated ketones of formula (I): (R 1 )(R 2 )C═CH—CH 2 —CH 2 —CO—R 3 (I), wherein R 1 is methyl or ethyl; R 2 is a saturated or unsaturated linear or cyclic hydrocarbon residue and R 3 is methyl or ethyl, wherein the process comprises reacting a tertiary vinyl carbinol of formula (II): (R 1 )(R 2 )C(OH)—CH═CH 2 (II), with an isopropenyl methyl or ethyl ether of formula (III): H 3 C—C(OR 3 )═CH 2 (III), in the presence of an ammonium (NH 4 + ) salt as catalyst.