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US 9,428,481 B2Granted
Process for the preparation of 2 substituted tetrahydropyranols
AssigneeBASF SE
InventorsGabriele Gralla, Ralf Pelzer
Life of this patent
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Abstract
The present invention relates to a process for the preparation of 2-substituted 4-hydroxy-4-methyltetrahydropyrans by reacting 3-methylbut-3-en-1-ol (isoprenol) with the corresponding alkenealdehydes in the presence of a strongly acidic ion exchanger with subsequent hydrogenation. Specifically, the present invention relates to a corresponding process for the preparation of 2-isobutyl-4-hydroxy-4-methyltetrahydropyran by reacting isoprenol with prenal, with subsequent hydrogenation.
Claims18
A process for the preparation of 2-substituted 4-hydroxy-4-methyltetrahydropyrans of the formula (I)
- where the radical
- R1 is a straight-chain or branched alkyl radical having 1 to 5 carbon atoms, and
- R2 is hydrogen or a straight-chain or branched alkyl radical having 1 to 3 carbon atoms,
- which comprises reacting isoprenol of the formula (II)
- with an aldehyde of the formula (III)
- wherein the radicals R1 and R2 have the same meanings as given in formula (I), in the presence of water and in the presence of a strongly acidic cation exchanger to form the compound of the formula (IV)
- and hydrogenation of the compound of the formula (IV) to give a compound of the formula (I), wherein the reaction is carried out in the presence of from 100 to 180 mol % of water, wherein the amount of water refers to the amount of isoprenol of the formula (II).
4 more elements
Dependencies are inferred from the claim text.