Method for the cyclization of gamma-delta, or delta-epsilon unsaturated alcohols
AssigneeAnic S.p.A.
InventorsAldo Prevedello, Maurizio Brunelli, Edoardo Platone
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Abstract
In the cyclization of gamma-delta or delta-epsilon unsaturated alcohols in order to obtain certain tetrahydrofuran and tetrahydropyran derivatives which are useful in the perfuming of detergents, the improvement consisting in that the alcohol to be cyclized is reacted with a cationic ion-exchange resin. The useful temperature range is from 20.degree. C. to 150.degree. C.: in practice the alcohol and the resin are boiled together or refluxed until the reaction is completed. A number of examples is reported and physicochemical data are given.
Claims12
A method for the cyclization of 3,7-dimethyl-3-hydroxy-6-octenenitrile comprising the step of contacting said nitrile with a cationic ion exchange resin at a temperature in a range of 20.degree. C. to 180.degree. C. or more, consistent with the stability of said resin which is employed in a weight ratio of resin to nitrile from an almost catalytic quantity to one or higher.
A method for the synthesis of 2,6,6-trimethyl-2-cyano-methyl tetrahydropyran characterized in that 3,7-dimethyl-3-hydroxy-6-octenenitrile is cyclized in the presence of a quantity of a cationic ion-exchange resin which is almost catalytic and at a temperature in the range 20.degree. C.-150.degree. C.
A method for the synthesis of 2-methyl-2-cyanomethyl-5-isopropyl tetrahydrofuran characterized in that 3,7-dimethyl-3-hydroxy-6-octenenitrile is cyclized in the presence of an almost catalytic quantity of a cationic ion-exchange resin and at temperatures which vary from 80.degree. C. to 180.degree. C. or above, consistent with the stability of the resin.
A method for the synthesis of 2-methyl-2-cyanomethyl-5-isopropyl tetrahydrofuran characterized in that 3,7-dimethyl-3-hydroxy-6-octenenitrile is cyclized in the presence of an amount of a cationic ion-exchange resin which is greater than catalytic until reaching a weight ratio of the resin to the alcohol equal to one or more.
A method for the synthesis of 2-methyl-2-cyanomethyl-5-isopropyl tetrahydrofuran characterized in that 3,7-dimethyl-3-hydroxy-6-octenenitrile is cyclized in the presence of a quantity of a cationic ion-exchange resin greater than a catalytic amount up to weight ratios of the resin to the alcohol equal to one or greater at temperatures which are variable from 80.degree. C. to 180.degree. C., or more consistent with the stability of the resin.
Dependencies are inferred from the claim text.