Enantiospecific preparation of [(2r,6s)-endo]-5-aza-1,10,10-trimethyl-3-oxatricyclo[5.2.1.02,6]decan-4-one by a nitrene-mediated route from [(1s)-endo]-(−)-borneol and its utility as a chiral auxiliary in some asymmetric transformations
作者:Malcolm R. Banks、Alexander J. Blake、J.I.G. Cadogan、Ian M. Dawson、Ian Gosney、Keith J. Grant、Suneel Gaur、Philip K.G. Hodgson、Kevin S. Knight、Glen W. Smith、Dian E. Stevenson (nee Thomson)
DOI:10.1016/s0040-4020(01)80472-5
日期:1992.1
successful chiral auxiliary by contemporary standards in a variety of asymmetric transformations, including alkylation, acylation, and aldol reactions for which high levels of asymmetric induction are observed. Diethylaluminium chloride-catalysed Diels-Alder reactions exhibit poorer selectivity except for the cinnamoyl derivative 23 which is stereospecific.
据报道,通过添加衍生自[(1s)-内]-(-)-降冰片基-对硝基苯磺酸氧碳酸酯4的旋光性烷氧基羰基氮化物5,尝试进行苯乙烯的手性叠氮化。在所采用的各种条件下均未观察到可测量的不对称感应,但是在没有烯烃的情况下,形成了三环恶唑烷-2-酮8,通过叠氮甲酸酯7的热分解(在1,1, 2,2-四氯乙烷(50%)或喷雾热解(58%)。恶唑烷酮-2-一8通过当代标准,已证明其在各种不对称转化中是成功的手性助剂,包括烷基化,酰化和醛醇缩合反应,其中观察到了高水平的不对称诱导。二肉桂氯化铝催化的Diels-Alder反应显示出较差的选择性,除了肉桂酰衍生物23是立体有择的。