Sterically Congested Molecules, 17. – Novel Syntheses of α,α,β-Tri-tert-butyl Compounds
作者:Gerald Böhrer、Rudolf Knorr、Petra Böhrer、Bernhard Schubert
DOI:10.1002/jlac.199719970128
日期:1997.1
corresponding Barbier variant takes a different course. Productive transformations of the α,α,β-tri-tert-butyl glycol 9 lead to α,β,β-tri-tert-butylethanone (17, overall 4 steps), or α,α,β-tri-tert-butylethene (20, 3 or 4 steps), or α,β,β-tri-tert-butyl-β-hydroxyethanone (19, 3 steps, also by Grignard addition to bipivaloyl 4). Steric congestion is assessed by searches for restricted internal rotation. The alkene
新戊(2)中,从新戊酸乙酯(制备1)或者从草酸二甲酯(3),发生反应与叔通过还原(45%正丁基锂10),并加入(45%9),而相应的变体Barbier的采用了不同的课程。α,α,β-三叔丁基乙二醇9的生产转化导致α,β,β-三叔丁基乙酮(共17步,共4步)或α,α,β-三叔丁基乙炔(20、3或4步)或α,β,β-三叔丁基-β-羟基乙酮(19,3个步骤,也可通过格氏试剂添加到bipivaloyl 4上)。通过搜索受限的内部旋转来评估立体肌充血。关于NMR分配和化学降解研究了烯烃20及其环氧化物27。