Asymmetric synthesis of cis-1,3-diamino-1,3-dideoxycyclitols

Abstract

Starting with the hetero-Diels–Alder reaction of the O- isopropylidene- protected cis-cyclohexa-3,5diene-1, 2-diol with (–)-2, 3:5, 6-di-O-isopropylidene-1-nitroso-α-D-manno-furanosyl chloride the optically pure (+)-endo-adduct was exclusively formed. After reduction of the NO bond and protection of the amino group, the second nitrogen function was introduced by participation of the neighbouring trichloroacetimidate group in the addition of iodine to the CC bond or in the epoxide opening of the corresponding tri-O-trichloroacetimidato-trans-epoxide derivative. Hydrolysis of the bicyclic dihydro-1, 3-oxazoles, complete acetylation, deiodonation if necessary, and final simultaneous removal of all protective groups yielded (–)-1 L-2,4-diamino-2,3,4-trideoxy-allo-inositol and (–)-1 L-2,4-diamino-2,4-dideoxy-chiro-inositol in good overall yields.

The absolute configuration of the hetero-Diels–Alder endo-adduct was determined by chemical transformation.