Patent ID: 9139549
Filing Date: 2015-09-22
Classification: C07D

Abstract:
1. A process for preparing 2-substituted 4-hydroxy-4-methyltetrahydropyrans of formula (I) and of 2-substituted 4-methyltetrahydropyrans of formula (II) in which R which comprises reacting a) 3-methylbut-3-en-1-ol of formula (III) b) subjecting the reaction product from step a) to a separation, giving a fraction comprising 2-substituted 4-hydroxy-4-methyltetrahydropyrans of formula (I) and a fraction which comprises at least one of the compounds (V.1), (V.2) or (V.3) and at least one dioxane compound (VI), c) subjecting the fraction which comprises at least one of the compounds (V.1), (V.2) or (V.3) and at least one dioxane compound (VI) to hydrogenation, d) isolating a fraction comprising 2-substituted 4-methyltetrahydropyrans (II) and a fraction comprising the at least one dioxane compound (VI) from the hydrogenation product obtained in step c).