Synthesis of 3-Alkyl Oxazolidines, Derived from 2-Hydroxymethyl Piperidine, as Analytical Standards for the Analysis of Volatile Aldehydes in the Workplace

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