Glycolonitrile Oligomerization: Structure of Isolated Oxazolines, Potential Heterocycles on the Early Earth
1997; American Chemical Society; Volume: 62; Issue: 16 Linguagem: Inglês
10.1021/jo962185r
ISSN1520-6904
AutoresGustaf Arrhenius, Kim K. Bladridge, Sarah E. Richards-Gross, Jay S. Siegel,
Tópico(s)Synthesis and Characterization of Heterocyclic Compounds
ResumoA study of glycolonitrile polymerization has led to the isolation and characterization of two 2,5-dihydro-4-aminooxazoles, 4 and 5. Previous reports have misassigned these structures as s-triazines or pyrimidines. X-ray diffraction analysis of crystals of 4 and an acetylated oxazole derivative of 5 (6) confirm the proposed structures. Ab initio computations are used to assess the relative thermodynamic stability of three trimer isomers (an s-triazine, an aminohydroxypyrimidine, and an aminooxazoline), and the results indicate that 4 is a novel kinetic product. Mechanistic considerations rationalize kinetic oxazole formation over the more customary triazine or pyrimidine trimers.
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