SYNTHETIC APPROACH TO N-ALKYLATED 2,5-DIAMINO-2,5-DIDEOXY-1,4-3,6-DIANHYDROALDITOLS BY REDUCTIVE ALKYLATION

N,N'-Dialkylated 2,5-diamino-2,5-dideoxy-1,4;3,6-dianhydroalditols, re presenting interesting basic catalysts for polyaddition reactions, are synthesized by different reductive alkylation procedures in satisfact ory yields. D-Gluco- and -2,5-diamino-2,5-dideoxy-1,4;3,6-dianhydroald itols 7-8,10-15 are accessible by reaction of the corresponding diamin es with carbonyl compounds and reduction of the intermediately formed imine. For the synthesis Of D-manno-N,N'-dialkylated diamines, an alte rnative route via 1,4;3,6-dianhydro-D-threo-2,5-hexodiulose (18) is es tablished, thus avoiding the six-step synthesis towards 1,4;3,6-dianhy dro-D-mannitol (2). Reductive alkylation of diketone 18 yields stereos pecifically only the alkylated diamine 21 with D-Manno-configuration. In case of the monoketones only 1,4;3,6-dianhydro-L-sorbose (16) can b e transformed stereospecifically to entyl-5-amino-5-deoxy-1,4;3,6-dian hydro-D-sorbitol (19), whereas 1,4;3,6-dianhydro-D-fructose (17) yield s a mixture of D-manno- and D-gluco-monoamines 20a and 20b by reductiv e alkylation with 2-pentylamine and sodium borohydride.