| Abstrakt: |
N-Benzyl-2-C:1-N-carbonyl-2-deoxy-5,6-O-isopropylidene-3-keto-α-D-ribohexo-furanosylamine (5), available by [2+2]cycloaddition of trichloroacetyl isocyanate to 1,4-anhydro-3-O-benzyl-5,6-O-isopropylidene-D-arabino-hex-1-enitol (1), was subjected to Baeyer-Villiger oxidation, and after transformation into tosyloxyimino compound 14, for Beckmann rearrangement to afford (1S, 3S, 6R, 4'R)- 8-aza-8-benzyl-3-(2',2'-dimethyl-dioxolanyl-4')-2,4-dioxa-5,7-dioxobicyclo[4.2.0]octane (12) and (1S, 3R, 6R, 4'R)-8-benzyl-5,8-diaza-3-(2',2'-dimeethyldioxolanyl-4')-4-ethoxy-2-oxa-7-oxobicyclo[4.2.0]oct-4-ene(15), respectively. Model studies of both reactions were performed using related 3-keto-1,2:5,6-di-O-isopropylidene-α-D-ribohexofuranose (6). |
