All articles of this category N , N ′-Dialkylated 2,5-diamnno-2,5-dideoxy-1,4;3, 6-dianhydroalditols, representing interesting basic catalysts for polyaddition reactions, are synthesized by different reductive alkylation procedures in satisfactory yields. D- Gluco - and L- ido - N , N ′-dialkyl-2,5-diamino-2,5-dideoxy-1,4;3,6-dianhydroalditols 7-8 , 10-15 are accessible by reaction of the corresponding diamines with carbonyl compounds and reduction of the intermediately formed imine. For the synthesis of D- manno - N , N ′-dialkylated diamines, an alternative route via 1,4;3,6-dianhydro-D-threo-2,5-hexodiulose ( 18 ) is established, thus avoiding the six-step synthesis towards 1,4;3,6-dianhydro-D-mannitol ( 2 ). Reductive alkylation of diketone 18 yields stereospecifically only the alkylated diamine 21 with D- manno -configuration. In case of the monoketones only 1,4;3,6-dianhydro-L-sorbose ( 16 ) can be transformed stereospecifically to N -2-pentyl-5-amino-5-deoxy-1,4;3,6-dianhydro-D-sorbitol ( 19 ), whereas 1,4;3,6-dianhydro-D-fructose ( 17 ) yields a mixture of D- manno - and D- gluco -monoamines 20a and 20b by reductive alkylation with 2-pentylamine and sodium borohydride.
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Limberg et al. (1994) studied this question.