催化甲基化法制备d-α-生育酚

Preparation of d-α-tocopherol by direct catalytic methylation

维生素E是由α、β、γ、δ-生育酚及α、β、γ、δ-三烯生育酚等八种化合物组成的混合物,它们的生理活性各异。在构象上,又有d-型和l-型之分,天然的多为d-型而人工合成的则多为d,l-型,天然的d-α-生育酚具有迄今所知的最大的维生素E活性。选用V2O5为催化剂进行了反应条件的优化,得到优化条件为:反应温度250℃、时间1 75h、催化剂用量为维生素E的3 5%、氢气压力0 3mPa(表压)。实验结果为:α-生育酚含量92.31%、维生素E得率为79 83%。

V_E is composed of α,β,γ,δ-tocopherol and α,β,γ,δ-tocotrienol which had different physiological activity and configurations. Natural tocopherols are mainly d-type,but most of chemically synthesized (tocopherols) are d,l-type.Natural d-α-tocopherol has the highest bioactivity in all kinds of V_E.When V_2O_5 was used as the catalyst for the converting of non-d-α-tocopherol, the optimal technological conditions were as following:reaction temperature 250℃,reaction time 1.75h, use level of catalyst 3.5%of V_E content,the pressure of hydrogen 0.3mPa(gauge pressure).The final results were α-(tocopherol) content 92.31% and V_E yield 79.83%.