Reduction of tocopherol chromenes with heterogeneous catalysts and deuterium gas resulted in various degrees of deuterium incorporation despite the use of high purity deuterium gas. Exchange of hydrogens on C-7 of γ-tocopherol was evident by 2H-NMR and could be controlled by consideration of the substrate (chromene) to catalyst ratio, concentration and temperature. Tocopherols deuterated at C3 and C4 were prepared with 94% d2 incorporation using 10% Pd/C at 0°C in ethyl acetate. Copyright © 2001 John Wiley & Sons, Ltd.
尽管使用了高纯度的
氘气,但使用异相催化剂和
氘气还原
生育酚色烯烃会导致不同程度的
氘掺入。通过 2H-NMR 可以明显看出γ-
生育酚 C-7 上的氢原子发生了交换,并且可以通过考虑底物(色烯)与催化剂的比例、浓度和温度来控制。使用 10% Pd/C,在 0°C 的
乙酸乙酯中制备 C3 和 C4 氚化
生育酚,d2 结合率为 94%。Copyright © 2001 John Wiley & Sons, Ltd. All Rights Reserved.