D-MANNITOL AS THE CHIRAL SOURCE FOR THE EPC SYNTHESIS OF BOTH ENANTIOMERS OF 3-ETHOXYCARBONYL-4-HYDROXY-2-ISOXAZOLINES AND HIGHLY FUNCTIONALIZED TRICYCLIC SYSTEMS

The EPC preparation of both enantiomers of cis- and trans 5-substitute d 4-hydroxy-2-isoxazoline 2-oxides has been achieved in an enantiodive rgent fashion starting from D-mannitol through the application of the tandem nitroaldol-cyclization reaction to enantiomerically pure alpha- mesyloxyaldehydes. These stereochemically labile aldehydes have been g enerated in situ and reacted under very mild domino conditions. Enanti omeric purity of the products has been assessed by H-1 NMR and HPLC an alyses of the corresponding Mosher's esters. The enantiomerically pure 4-hydroxy-2-isoxazoline a-oxides have been employed as pivotal interm ediates for the EPC preparation of the corresponding deoxygenated deri vatives and highly functionalized tricyclic systems (HFTS) 1, useful f or the preparation of 2-aminopolyols and alpha,alpha-disubstituted pol yhydroxy amino acids.