Dsm IP Assets B.v.

Claus Dittel

Werner Bonrath

Thomas Netscher

Thomas Heinrich Pabst

Rudolf Schmid

Lisa Giraudi

Thomas Pabst

A process for the manufacture of 3-phytyl-2,5,6-trimethylhydroquinone-1-acetate, and optionally therefrom tocopheryl acetate, comprises either C-alkylating 2,3,6-trimethylhydroquinone-1-acetate with isophytol or phytol in the presence of a sulphur(VI) containing catalyst of the formula RSOOH, wherein Rsignifies hydroxy, halogen, lower alkyl, halogenated lower alkyl or aryl, in an aprotic organic solvent, or O-alkylating 2,3,6-trimethylhydroquinone-1-acetate with a phytyl halide in a polar aprotic organic solvent in the presence of a base, and subjecting the so-obtained 4-O-phytyl-2,3,6-trimethylhydroquinone-1-acetate to a rearrangement reaction, and in each case optionally submitting the so-obtained 3-phytyl-2,5,6-trimethylhydroquinone-1-acetate to a ring closure reaction to produce tocopheryl acetate. The invention also includes the novel compound 3-phytyl-2,5,6-trimethylhydroquinone-1-acetate and certain stereoisomers thereof, and also the further novel compound 4-hydroxy-2,3,6-trimethyl-5-[3-(4,8,12-trimethyltridecyl)-but-3enyl]phenyl acetate which itself is one of several isomers of 3-phytyl-2,5,6-trimethylhydroquinone-1-acetate formed by isomerization under the influence of heating, e.g. during its distillation as part of the isolation and purification procedure following its manufacture as indicated above. (All-rac)-&#x3b1;-tocopherol, which may be derived from its acetate, is known to be the most active industrially important member of the vitamin E group.

Manufacture of tocopheryl acetate

The present invention is concerned with a novel process for the manufacture of &#x3b1;-tocopheryl acetate which comprises reacting 2,3,6-trimethylhydroquinone-1-acetate with a compound selected from the group consisting of phytol (formula IV with R&#x2550;OH), iso-phytol (formula III with R&#x2550;OH), and (iso) phytol derivatives represented by the following formulae III and IV with R&#x2550;C-to C-alkonoyloxy, benzoyloxy, mesyloxy, bezenesul-fonyloxy or tosyloxy, (IV) in the presence of a catalyst of the formula M(RSO), wherein Mis a silver, copper, gallium, hafnium or rare earth metal cation, n is the valence of the cation M, and Ris fluorine, C-perfluoroalkyl or perfluoroaryl, and, if required, cyclizing any 3-phytyl-2,5,6-trimethylhydroquinone-1-acetate or a double bond isomer thereof obtained as an intermediate reaction product, to produce &#x3b1;-tocopheryl acetate. In the catalyst Mis preferably Ag, Cu, Ga, Sc, Lu, Ho, Tm, Ybor Hf.

Process for the manufacture of &#x3b1;-tocopheryl acetate

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Solothurn, Switzerland

Claus Dittel