Abstract
The present study demonstrates a synopsis of the scientific researches reported on the different reactions of oxazolo[3,2-a]pyridines, besides the preparation of significant fused heterocycles up till now. The different main sections that described the reactivity of the inspected analogues include stereoselective alkylation, reactions involved oxazolidine ring, synthesis of polycyclic systems, indole alkaloids, and alkyl amines. The stereochemical selectivity of oxazolopiperidone lactams is studied, in which the configuration of the stereocenter C8a and substituents at the C8 and C8a effect on the stereoselectivity. On the other hand, the synthetic consequence of the alkylation products provides diverse routes for the synthesis of substituted enantiopure piperidines that are used for the synthesis of natural products, for example, (-)-rhazinilam, (+)-eburnamonine, (+)-aspidospermidine, indole alkaloids such as dihydrocleavamine, nor-20-epiuleine, (+)-dasycarpidone, (+)-uleine, indoloquinolizidine, (+)-dihydrocorynantheine, (-)-dihydrocorynantheol, and indolizines, eg, octahydroindolizines, monomorine I, (-)-S-coniceine, and (-)-R-coniceine.