728894-66-4Relevant academic research and scientific papers
PROCESS FOR THE MANUFACTURE OF α-TOCOPHERYL ACETATE
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Page 9, (2008/06/13)
The present invention is concerned with a novel process for the manufacture of α-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 = OH), iso-phytol (formula III with R = OH), and (iso) phytol derivatives represented by the following formulae III and IV with R = C2-to C5-alkonoyloxy, benzoyloxy, mesyloxy, benzenesul-fonyloxy or tosyloxy, (IV) in the presence of a catalyst of the formula Mn+(R1SO3-)n, wherein Mn+ is a silver, copper, gallium, hafnium or rare earth metal cation, n is the valence of the cation Mn+, and R1 is fluorine, C1-8-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 α-tocopheryl acetate. In the catalyst Mn+ is preferably Ag+, Cu+, Ga3+, Sc3+, Lu3+, Ho3+, Tm3+, Yb3+ or Hf4+.
MANUFACTURE OF TOCOPHERYL ACETATE
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Page 12-13, (2008/06/13)
A process for the manufacture of 3-phytyl-2,5,6-trimethylhydroquinone-l-acetate, and optionally therefrom tocopheryl acetate, comprises either C-alkylating 2,3,6-trimethylhydroquinone-l-acetate with isophytol or phytol in the presence of a sulphur(VI) containing catalyst of the formulaR1SO2OH, wherein Rl signifies hydroxy, halogen, lower alkyl, halogenated lower alkyl or aryl, in an aprotic organic solvent, or O-alkylating 2,3,6-trimethylhydroquinone-l-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-l-acetate to a rearrangement reaction, and in each case optionally submitting the so-obtained 3-phytyl-2,5,6-trimethylhydroquinone-l-acetate to a ring closure reaction to produce tocopheryl acetate. The invention also includes the novel compound 3-phytyl-2,5,6-trimethylhydroquinone-l-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-l-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)-α -tocopherol, which may be derived from its acetate, is known to be the most active industrially important member of the vitamin E group.
