Variable Strategy toward Carbasugars and Relatives. 5.<sup>1</sup> Focus on Preparation of Chiral Nonracemic Medium-Sized Carbocycles
作者:Gloria Rassu、Luciana Auzzas、Luigi Pinna、Vincenzo Zambrano、Franca Zanardi、Lucia Battistini、Enrico Gaetani、Claudio Curti、Giovanni Casiraghi
DOI:10.1021/jo0344539
日期:2003.7.1
dienoxysilanes, 6 and 12, in the synthesis of carbasugar frameworks is illustrated by the preparation of the scantily investigated carbaseptanose and carbaoctanose representatives of this class of compounds. The target compounds, 1, 2, 3, ent-2, ent-3, and 4, were obtained from readily available carbohydrate precursors (5 and 19) in yields of 21-30% over 8-12 steps. The irreversible silylative ring-closing
由呋喃和吡咯基二烯氧基硅烷6和12依次进行的乙烯基醇醛(分子间)/甲硅烷基化醇醛(分子内)加成反应在合成巴西棕榈糖骨架中的可行性由制备的经过仔细研究的羧甲基淀粉和羧甲基淀粉代表这类化合物。从易于获得的碳水化合物前体(5和19)以8至12个步骤以21-30%的产率获得目标化合物1、2、3,ent-2,ent-3和4。由TBSOTf / Pr(i)(2)驱动的γ-取代的二氢-5H-呋喃-2-酮和吡咯烷酮-2-一醛(9、16,ent-16和22)的不可逆的甲硅烷基闭环羟醛化反应EtN Lewis酸-刘易斯碱对被证明是一种实用的,非对映选择性的操作,可以锻造出高密度官能化的,