GB629649A - Improvements in preparation of materials having vitamin e activity - Google Patents

Abstract

Gamma tocopherol, or a concentrated solution thereof, is treated by methods known to be capable of introducing an alkyl, an aryl or an aralkyl group into a benzene nucleus containing a hydroxyl group, the vitamin E activity being thus increased. The invention is particularly directed to the introduction of a methyl group in the 5 position in the nucleus of gamma tocopherol so as to convert it into alpha tocopherol. Halogen alkyl groups which, after introduction may be reduced to the corresponding alkyl group, include the chloromethyl group which is introduced by reacting gamma tocopherol with chloromethyl ether or with a 40 per cent aqueous solution of formaldehyde, paraformaldehyde or dimethylformal in the presence of hydrogen chloride, hydrogen bromide or hydrogen iodide; paraldehyde or diethyl formal or propionaldehyde may replace formaldehyde to provide the corresponding halogen alkyl group. In an example, to 3.3 gms. of a tocopherol concentrate prepared by molecular distillation of soya bean oil, dissolved in 75 ccs. ether was added 0.4 gms. of paraformaldehyde and 0.4 gms. of zinc chloride. Hydrogen chloride gas was passed into the suspension for 15 minutes at room temperature and the mixture allowed to stand overnight when it was washed with water, dried and evaporated to give an oil which was reduced with zinc-mercury amalgam and concentrated hydrochloric acid in ethanol. In other examples, ethereal solutions of gamma tocopherol, or gamma tocopherol concentrate, are treated (1) with aqueous formalin, concentrated hydrochloric acid and hydrogen chloride gas; (2) with chloromethyl ether; (3) with aqueous formalin and concentrated hydrochloric acid and the resultant products reduced as above, with zinc powder. A sample has been furnished under Sect. 2 (5) of benzyl tocopherol prepared by treating a tocopheral concentrate with benzaldehyde and hydrogen chloride followed by reduction with zinc dust.