Highly regioselective and diastereoselective intramolecular chiral nitrone cycloaddition reactions with a vinyl group tethered by a silicon atom have been developed as a general method for the synthesis of stereodefined amino polyols. This strategy features a series of one-pot reactions involving (1) DIBAH reduction of the carbonyl groups of chiral α- or β-hydroxy carbonyl compounds, in which the hydroxy group is protected as diphenylvinylsilyl ethers, at -78 °C to give an aldehyde, (2) condensation of the aldehyde with N-benzylhydroxylamine to furnish nitrone (-78 °C → rt), and (3) intramolecular [3 + 2] dipolar cycloaddition reaction between the nitrone and the silicon-tethered vinyl group (rt → 70 °C, 3-15 h) to give isoxazolidine derivatives as direct precursors for amino polyols. Since the cycloaddition reaction is concerted in nature and passes through a fused-bicyclic transition state, the substituents, the nitrone substrate, and the silicon atom bias the stereochemical course of this addition, resulting in highly diastereoselective and synthetically useful transformations.
ASJC Scopus subject areas
- Colloid and Surface Chemistry