Efficient, Stereoselective Synthesis of Oxazolo[3,2-<i>a</i>]pyrazin-5-ones: Novel Bicyclic Lactam Scaffolds from the Bicyclocondensation of 3-Aza-1,5-ketoacids and Amino Alcohols
作者:Josef R. Bencsik、Timothy Kercher、Michael O'Sulliva、John A. Josey
DOI:10.1021/ol030065h
日期:2003.7.1
[reaction: see text] The bicyclocondensation of 3-aza-1,5-ketoacids and amino alcohols furnished novel oxazolo[3,2-a]pyrazin-5-one scaffolds possessing angular, ring junction substituents in high yield with excellent levels of substrate-based diastereocontrol. Mild oxidation of serinol-derived scaffolds provided access to a new class of constrained dipeptide surrogates. Deprotection of the endocyclic
[反应:见正文] 3-氮杂-1,5-酮酸和氨基醇的双环缩合反应提供了新颖的恶唑并[3,2-a]吡嗪-5-酮支架,该支架具有高产率的角,环连接取代基,且具有极好的环磷酰胺水平基于底物的非对映控制。丝氨酸衍生的支架的轻度氧化提供了一种新的受约束的二肽替代物。这些支架中所含的内环胺的脱保护作用允许通过N-官能化进一步多样化。