The synthesis of 1,4,7-trimethyloxatriquinane (1), a 3-fold tertiary alkyl oxonium salt, is described. Compound 1 is inert to solvolysis with alcohols, even at elevated temperatures, but undergoes facile substitution with the strongly nucleophilic azide anion. Since an SN1 pathway is excluded, the only reasonable mechanistic interpretation for the reaction between 1 and N3 - is SN2, despite the fact that substitution is occurring at a tertiary carbon center. This finding is supported by computational modeling and a study of the reaction kinetics, and is also consistent with observed solvent and salt effects.
ASJC Scopus subject areas
- Colloid and Surface Chemistry