Synthesis of 3-alkyl oxazolidines, derived from 2-hydroxymethyl piperidine, as analytical standards for the analysis of volatile aldehydes in the workplace

Type de document

Études primaires

Année de publication

2023

Langue

Anglais

Titre de la revue

ACS Omega

Première page

26793

Dernière page

26805

Résumé

Hexahydro-3-alkyl-3H-oxazolo[3,4-a]pyridines 4–15 for the quantitative analysis of various aldehydes were obtained in good yield via the condensation reaction of 2-hydroxymethylpiperidine (2-HMP) with aldehydes under mild conditions. When acrolein was used, the bicyclic 17 was obtained. This novel compound has suitable physical characteristics for an analytical standard. The hexahydro-3-vinyl-3H-oxazolo[3,4-a]pyridine 16 can be obtained at higher temperatures using an excess of acrolein (3 equiv). Following the same procedure as for 16, but with an excess of 2-HMP (2 equiv), a diastereomeric mixture of 18/19, which are both bisadducts of 2-HMP with acrolein, was obtained. The latter mixture can be easily converted into pure 18. Mechanistically, a thorough 1H-NMR study did not show any evidence that the condensation reaction proceeded via an enamine. The reaction probably proceeded through an elusive hemiaminal and fleeting iminium ion, which underwent subsequent cyclization to give hexahydro-3-alkyl-3H-oxazolo[3,4-a]pyridines 4–16. The reaction pathways for the preparation of 4–18 are described.

Mots-clés

Piperidine, CAS 110894, Composés organiques volatils, Volatile organic compounds, Aldéhydes, Aldehydes, Évaluation de l'exposition, Exposure evaluation, Acroléine, Acrolein, CAS 107028

Numéro de projet IRSST

n/a

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