Reversal of diastereofacial selectivity in the intramolecular michael addition of -α-carbamoyloxy-α,β-unsaturated esters. Synthesis of N-benzoyl-,-daunosamine
作者:Masahiro Hirama、Takeo Shigemoto、Shô Itô
DOI:10.1016/s0040-4039(00)89313-2
日期:1985.1
Contrary to the precedents, 1,3-anti stereoselection was found in the intramolecular Michael addition of ethyl ,5-carbamoyloxy-4-trialkylsilyloxy-2-hexenoate to culminate in a synthesis of N-benzoyl-,-daunosomine. The antiperiplanar effect due to the group at 4-position was revealed to play a major role in the stereoselection in this type of reactions. N-benzoyl-,-3-epidaunosamine was also synthesized
与先例相反,在分子内迈克尔加成乙基,5-氨基甲酰氧基-4-三烷基甲硅烷基氧基-2-己酸酯的过程中发现了1,3-反立体选择,最终合成了N-苯甲酰基- ,-十二烷基亚胺。揭示了归因于4位基团的抗腹膜平面作用在这种类型的反应的立体选择中起主要作用。还通过1,2-syn不对称诱导合成了N-苯甲酰基- ,-3-表柔胺酸。