| 摘要 |
Diglycosyl diseleaides of formula a(n)-Se-Se-(n)G (I), seleno-glycosia of formula G(1)-Se-R (II), seleno-disaccharides of formula G(1)-Se-(a)G1 (III) and seleno-polysaccharides of formula -(Gi(1)-Se-(n)Gi+1)-p+1 a = glycosyl, opt. with OH gps. protected; n = 1-6 (i.e. the position at which G is bonded; cpds. (I) are symmetrical, i.e. both G and both n are the same; in (II) and (III) the G-Se bond is on the anomeric C in the 1-position; R = alkyl, alkenyl or aryl (opt. substd.); G1 = as G (same or different); G and G1 are in alpha- or beta-anomeric configuration; p = integer; i = 1 to p successively for the p+1 monomer units G1, Gi+1 = as G (same or different). Also clainmed is process for stereospecifica glycoxylation on the 1-position carbon, by reacting (II) (having predetermined alpha- or beta-anomer configuration and pref. with the OH gps. protected) with a glycozyl acceptor R1OH in presence of a "soft" promoter, to give a glycosyl cpd. of formula GOR1 (IV) having the opposite (beta or alpha) C-1 anomeric configuration to (II). The OH gps. of the prod. are opt. subsequently deprotected. R1 = hydrocarbyl, pref. opt. substd. alkyl or alkenyl or glycosyl (sic). USE/ADVANTAGE - (III) and (A) have the same applicatons as their thio analogues, i.e. as enzyme inhibitors, reactants for purifying enzyme, antidiabetic agents and antiviral agents (esp. for treatment of AIDS). They are also useful as non-toxic agents for introducing selenium into the body. (II) are stereospecific glyucosylating agents for prepn. of (IV) as descrbed above, esp. used in the prepn. of polysaccharides. (I) are intermediates for (II), (III) and (A). No uses are given for (IV). (II) provide stereospecificity of more than 95% in glysocylations.
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