Total syntheses of (+)- and (-)-1-deoxynojirimycin (1,5-dideoxy-1,5-imino-D- and L-glucitol) and of (+)- and (-)-1-deoxyidonojirimycin (1,5-dideoxy-1,5-imino-D- and L-iditol) via furoisoxazoline-3-aldehydes

The isoxazoline obtained by 1,3-dipolar cycloaddition of 2,2-diethoxyacetonitrile N-oxide to furan was converted into enantiomerically pure (-)-(3aS,5S,6S,6aR)- and (+)-(3aR,5R,6R,6aS)-3a,5,6,6a-tetrahydro-5,6-isopropylidenedioxyfuro [2,3-d]isoxazole-3-carbaldehyde, (-)-5 and (+)-5, respectively, through resolution with (1S,2S)-1,2-diphenylethylenediamine. The aldehydes 5 are required as latent 1,5-iminohexitol moieties in cross-aldolizations towards imino-C-disaccharides. In order to establish absolute configurations of 5, and to probe the projected uses, (+)-5 was converted into(+)-1-deoxynojirimycin [(+)-1, 3 steps, 58%] and into(-)-1,5-dideoxy-1,5-imino-L-iditol [(-)-2, 4 steps, 40%] adopting stereoselective routes. Similarly, (-)-1,5-dideoxy-1,5-imino-L-glucitol ((-)-1) and (+)-1,5-dideoxy-1,5-imino-D-iditol ((+)-2) were obtained with the same ease. (C) 1998 Elsevier Science Ltd. All rights reserved.