Asymmetric synthesis. Part 6. Copper salt promoted grignard reagent additions to ethyl 2,3-dideoxy-4,5:6,7-di-O-isopropylidene-D-arabino-trans-hept-2-enonate and subsequent formation of optically active 2-alkyl (or aryl) butane-1,4-dioic acids and butyro-1,4-lactones
作者:Ian W. Lawston、Thomas D. Inch
DOI:10.1039/p19830002629
日期:——
The copper-salt promoted 1,4-additions of aryl and t-butyl Grignard reagents to ethyl 2,3-dideoxy-4,5:6,7-di-O-isopropylidene-D-arabino-trans-hept-2-enonate are highly stereoselective yielding products with the D-manno-configuration. In contrast isopropyl and ethyl Grinard reagents give products preponderantly with the D-gluco-configuration. Cyclohexylmagnesium bromide does not react stereoselectively
铜盐促进芳基和叔丁基格氏试剂的1,4-增补乙基-2,3-二脱氧-4,5-:6,7-二- ö异亚丙基d -阿拉伯-反式-庚-2- enonate是高度立体收益产品与d -甘露-构型。相比之下异丙基和乙基格氏试剂,得到的产品主要发生与d -葡萄糖-构型。环己基溴化不立体选择性反应,但给出了一个55:在45混合物d -葡糖-和d -甘露-异构体。碳水化合物分子的受控降解提供了2-芳基(烷基)丁烷-1,4-二酸和3-芳基(烷基)-丁酰基-1,4-内酯。这些产物的对映体纯度是通过参考已知产物或通过使用光学活性nMR位移试剂来确定的。