Utilização de gama-glucono-1,5-lactona em síntese orgânica

Abstract

In This work were studied the use of 6-glucono-1,5-lactone 41 and its derivative 42 in organic syntnesis. Three main routes envolving a nucleophilic addition to 42 were explored. The first one intended to prepare D-arabinose 47 through addition of azide ion (N3-) followed by Curtius Rearangeroent. However the reaction followed another direction producing a triazinone 49e, which makes this route useless for preparing 47. The second worK involved the addition of several aliphatic and aromatic amines to 42 for producing acetonides of D-gluconamides. Various amides were produced (3,4:5,6-di-D-isopropilidene-D-gluconociclohexilamide 75%, 3,4:5,6-di-D-isopropilictene-D-gluconobutilamide 70%, 3,4:5,6-di-D-isopropilidene-D-gluconobenzilamide 90%, 3,4:5,6-di-D-isopropilidene-D-gluconodecilamide 73%, D-gluconephenilamide-D-glicose and D-gluconepheniamide-D-manose 1 : 1,45; 3,4:5,6-di-D-sopropilidene-D-gluconodibutilamide 100% and 3,4:5,6-di-D-isopropilidene-D-gluconodiisopropilamide 100%) in good yields, but the reaction is very sensitive to the nucleophilicity of the amines and experimental conditions. Tne third route studied the addition of alkyl litium for producing C-glicosides. However double alquilation product 64 was observed instead at the disired ketone 63. A possible explanation is related to the kinetics ot the reaction. Tne addition to ketone 63 is faster than to the starting material 42.