Jolita Bruzgulienė; Greta Račkauskienė; Aurimas Bieliauskas; Vaida Milišiūnaitė; Miglė Dagilienė; Gita Matulevičiūtė; Vytas Martynaitis; Sonata Krikštolaitytė; Frank A. Sløk; Algirdas Šačkus
Beilstein J. Org. Chem., 2022, 18, 102-109
https://doi.org/10.3762/bjoc.18.11

Abstract

A convenient and efficient synthesis of novel achiral and chiral heterocyclic amino acid-like building blocks was developed. Regioisomeric methyl 5-(N-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, 1H, 13C, and 15N NMR spectroscopy, HRMS, and single-crystal X-ray diffraction data.