Glycolonitril Oligomerization: Structure of Isolated Ozazolines, Potential Heterocycles on the Early Earth
G. Arrhenius*, K.K. Baldridge, S. Richards-Gross and J.S. Siegel

Scrippts Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093-0236

ABSTRACT

A 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 aminohydroxyopyrimidine, and an aminoozazoline), 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.

©Copyright 2002 Arrhenius Laboratory - All Rights Reserved