A convenient and efficient synthesis of novel achiral and chiral heterocyclic amino acid-like building blocks was developed. Regioisomeric methyl 5-(-Boc-cycloaminyl)-1,2-oxazole-4-carboxylates were prepared by the reaction of β-enamino ketoesters (including azetidine, pyrrolidine or piperidine enamines) with hydroxylamine hydrochloride. Unambiguous structural assignments were based on chiral HPLC analysis, H, C, and N NMR spectroscopy, HRMS, and single-crystal X-ray diffraction data.
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| http://dx.doi.org/10.3762/bjoc.18.11 | DOI Listing |
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