STEROIDS AND RELATED NATURAL PRODUCTS: XXX. SELECTIVE REDUCTION OF ESTERS. PART A. BENZOATES
作者:George R. Pettit、Brian Green、George L. Dunn、Peter Hofer、William J. Evers
DOI:10.1139/v66-191
日期:1966.6.1
Previously, reagents such as sodium borohydride – boron trifluoride were shown to be capable of reducing typical aliphatic esters and lactones to the corresponding ether derivatives. Under the same reaction conditions, a variety of benzoate esters (Ib, IIb, III, and V) were essentially unaffected. Resistance to attack was illustrated by conversion, with sodium borohydride – boron trifluoride, of 3
以前,硼氢化钠 - 三氟化硼等试剂已被证明能够将典型的脂肪族酯和内酯还原为相应的醚衍生物。在相同的反应条件下,多种苯甲酸酯(Ib、IIb、III 和 V)基本不受影响。通过硼氢化钠 - 三氟化硼将 3-oxo-17β-benzoyloxy-5α-androstane (III) 转化为 3β-hydroxy-17β-benzoyloxy-5α-androstane (IV) 和利血平 (V ) 变成酒精 VI。对于酮 VII 或醇 IXa 型的芳基-碳-氧键,与硼氢化钠-三氟化硼的反应通常会导致苄基-氧键(例如 X → XI)的还原裂变。在含有可用β-氢(例如IXc)的叔苄醇的情况下注意到了一个例外。这里,例如,脱水产生烯烃 XIIb 似乎是更有利的反应过程。硼氢化钠反应性的显着差异 - ...