Lewis Jason G, Bartlett Paul A
Center for New Directions in Organic Synthesis, Department of Chemistry, University of California, Berkeley, California 94720-1460, USA.
J Comb Chem. 2003 May-Jun;5(3):278-84. doi: 10.1021/cc020082i.
The incorporation of alpha-amino acids into heterocyclic structures is an effective strategy for generating peptidomimetics and combinatorial library scaffolds. This report describes the synthesis of novel bicyclic aminal lactones 3 by base-catalyzed cyclization of N-(2-oxoalkyl)-dipeptide esters 8. Assembly of the acyclic precursor 8 can be carried out on solid phase, with variation at four positions; cyclative release ensures high product purity in the final step. Cyclization affords the exo isomer stereospecifically when one chiral center is present in the precursor, or when both amino acids have the same configuration.
将α-氨基酸引入杂环结构是生成拟肽和组合文库支架的有效策略。本报告描述了通过N-(2-氧代烷基)-二肽酯8的碱催化环化反应合成新型双环缩醛内酯3。无环前体8的组装可以在固相上进行，在四个位置上有变化；环化释放确保了最后一步的高产物纯度。当前体中存在一个手性中心时，或者当两个氨基酸具有相同构型时，环化反应立体专一性地生成外型异构体。
