Preparation of d- alpha -tocopherol from natural intermediates

d- alpha -Tocopherol is prepared from a mixture obtained from natural intermediates and containing alpha -, beta -, gamma - and delta -tocopherols, by methylation at the aromatic ring of the tocopherols by reaction with formaldehyde or with a compound which donates formaldehyde under the reaction conditions, and subsequent catalytic hydrogenation, by a process in which the reaction with formaldehyde or with the formaldehyde donor is carried out at from 150 DEG to 200 DEG C. in the presence of an alkyl ester of phosphoric or phosphorous acid.