Chiroptical properties of tetrahydropyran-3,4-diols and 2-hydroxymethyltetrahydropyran-3-ols derived from l-arabinose, d-galactose, d-glucose, and d-xylose, and enantioselectivity in reduction with their complexes
作者:Günther Snatzke、Zlata Raza、Ivan Habuš、Vitomir Šunjić
DOI:10.1016/0008-6215(88)84002-3
日期:1988.11
lithium aluminium hydride has been studied. Low enantiomeric excess (⩽15%) was obtained, which was enhanced when an achiral modifier (ethanol, 2-propanol) was added to the complexes 10 and 11 prepared in situ . Enantioselective catalytic hydrogenation of Z -α-acetamidocinnamic acid was performed with the Rh(I)-norbornadiene complexes 2f and 4f , derived from the cis compounds 2a and 4a ; substantially
摘要(3 R,4 R)-(1a)和(3 S,4 R)-四氢吡喃-3,4-二醇(2a)和(2 R,3 S)-(3a)和(2 R,3 R -2-羟甲基四氢吡喃-3-醇(4a),分别衍生自d-木糖,l-阿拉伯糖,d-葡萄糖和d-半乳糖,在结构上是最简单的双齿配体手性碳水化合物型前体。这些二醇与[Mo 2(OAc)4]以及苯甲酸酯(1b-4b)和甲苯磺酸酯(1c-4c)以及铜(I)配合物(1d-4d)之间的二齿配合物的cd光谱讨论了二苯基次膦酸酯(1e–4e)。研究了反式化合物1a和3a与氢化铝锂的配合物(分别为10和11)将苯乙酮对映选择性还原为S(R)-1-苯基乙醇。低的对映体过量(⩽15%),当将非手性改性剂(乙醇,2-丙醇)添加到就地制备的配合物10和11中时,其增强。用衍生自顺式化合物2a和4a的Rh(I)-降冰片二烯配合物2f和4f进行Z-α-乙酰氨基二甲酰胺酸的对映选择性催化加氢;对