| 摘要 |
<p>Selective preparation of alpha -tocopherol (I) from other tocopherols (II) comprises catalytic permethylation using: (i) methanol in the near-critical or supercritical pressure and temperature region or a mixture of hydrogen and carbon monoxide and/or carbon dioxide equivalent to methanol, as methylating agent; and (ii) a mixed oxide catalyst prepared from hydrotalcite, containing at least copper and magnesium oxides and at least one trivalent metal oxide.</p> |
