Highly diastereoselective Michael addition of lithiated camphor imines of glycine esters to α,β-unsaturated esters. Synthesis of optically pure 5-oxo-2,4-pyrrolidinedicarboxylates of unnatural stereochemistry
Highly diastereoselective Michael addition of lithiated camphor imines of glycine esters to α,β-unsaturated esters. Synthesis of optically pure 5-oxo-2,4-pyrrolidinedicarboxylates of unnatural stereochemistry
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甘氨酸酯的锂化樟脑亚胺与 α,β-不饱和酯的高度非对映选择性迈克尔加成合成非天然立体化学的光学纯 5-氧代-2,4-吡咯烷二甲酸酯。
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
E. Wada
中科院分区：
文献类型：
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作者：
S. Kanemasa;A. Tatsukawa;E. Wada
甘氨酸酯的樟脑亚胺的烯醇化锂对α，β-不饱和酯进行了高度非对映选择性的Michael加成。Z，E烯醇酯的紧密螯合结构和α，β-不饱和酯对烯醇酯表面的选择性接近是观察到的高非对映选择性的原因。烷基烯丙二酸酯受体的使用导致了迈克尔加合物的非对映特异性形成。去除加合物的樟脑助剂和伴随的环化得到光学纯的非自然立体化学的5-氧-2,4-吡咯烷二羧基对映体
The lithium enolates of camphor imines of glycine esters underwent highly diastereoselective Michael additions to α,β-unsaturated esters. The tightly chelated structure of the Z,E enolates and the selective approach of the α,β-unsaturated esters to the re face of the enolates were responsible for the high diastereoselectivity observed. The use of alkylidenemalonate acceptors led to the diastereospecific formation of Michael adducts. Removal of the camphor auxiliary of the adducts and concomitant cyclization led to optically pure enantiomeric 5-oxo-2,4-pyrrolidinedicarboxylates of unnatural stereochemistry