Patent ID: 6329554
Filing Date: 2001-12-11
Classification: B01D,B01J,C07C,Y02P

Abstract:
A process for the continuous preparation of unsaturated ketones of formula I ##STR10##where the dashed line can be an additional C--C bond, R.sup.1 is a branched or unbranched alkyl having from 1 to 4 carbons and R.sup.2 is a saturated or unsaturated, branched or unbranched, unsubstituted or methoxy-substituted aliphatic hydrocarbon radical having 1 to 37 carbons, a cycloalkyl having from 4 to 12 carbons or a cycloalkyl alkyl having 5 to 30 carbons, by reacting an unsaturated alcohol of the formula II ##STR11##where R.sup.1 and R.sup.2 have the meanings given above, with an alkyl acetoacetate of the formula III ##STR12##where R.sup.3 is a branched or unbranched alkyl having from 1 to 5 carbons, in the presence of organic aluminum compound as catalyst which comprisesA. reacting the unsaturated alcohol of the formula II with the alkyl acetoacetate of the formula III on the internals of a fractionation tower to give the acetoacetate of the unsaturated alcohol and separating off the resultant alcohol of the formula IVR.sup.3 --OH (IV)with the overhead stream of the fractionation tower andB. rearranging the resultant acetoacetate of the alcohol of the formula II into the unsaturated ketone of the formula (I) in the presence of the organic aluminum compound in the lower part of the fractionation tower and/or in the bottom of the fractionation tower, the carbon dioxide forming in this case passing via the fractionation tower into the overhead stream and the resultant unsaturated ketone of the formula (I) being separated off from the fractionation tower via the bottom.