Approaches to the Synthesis of Glycosides

In a search for better synthetic routes to O- and S-glycosides, a number of mercury(II) containing derivatives of 1-thio-D-glucose were synthesised, and their reactions with thiols and acids were investigated as well as their pyrolytic behaviour. A new route to O-acetylated glycosyl thiols involving specific S-deacetylation of peracetylated 1-thioglycoses was developed by the conversion of 1-thio-Beta-D-glucopyranose pentaacetate into tetra-O-acetyl-1-S-phenylmercury (II) thio-Beta-D-glucopyranose and subsequent demercuration of this by hydrogen sulphide. A range of acylated alkyl and aryl 1,2-trans-1-thioglycosides was prepared by one step processes from peracylated 1,2-trans-related sugars by a procedure which involved the use of equimolar proportions of thiols together with boron trifluoride. A similar procedure was used to obtain benzoylated 1,2-cis-O-glucosides from penta-O-benzoyl-Beta-D-glucopyranose. Partial desulphurisation of acetylated glucosyl phenyl disulphide with tris(diethylamino)phosphine led to both phenyl tetra-O-acetyl-1-thio-alpha-D-glucopyranoside and the alpha, beta-linked thiotrehalose peracetate. Phenyl 1-thiohex-1-enopyranosid-3-ulose esters were obtained from the light induced reactions of N-bromosuccinimide with acetylated and benzoylated phenyl 1-thiogluco- and galacto-pyranosides; the acetylated 1-thioglycosides gave mixtures of 2-O-acetyl and 2-O-monobromoacetyl 1-enosid-3-uloses. Methyl hexuronate derivatives were brominated alpha to the carbonyl function by N-bromosuccinimide, and a new synthetic route to L-ascorbic acid has been proposed following the successful bromination of methyl tri-O-acetyl-2,6-anhydro-L-gulonate

Approaches to the Synthesis of Glycosides

In a search for better synthetic routes to O- and S-glycosides, a number of mercury(II) containing derivatives of 1-thio-D-glucose were synthesised, and their reactions with thiols and acids were investigated as well as their pyrolytic behaviour. A new route to O-acetylated glycosyl thiols involving specific S-deacetylation of peracetylated 1-thioglycoses was developed by the conversion of 1-thio-Beta-D-glucopyranose pentaacetate into tetra-O-acetyl-1-S-phenylmercury (II) thio-Beta-D-glucopyranose and subsequent demercuration of this by hydrogen sulphide. A range of acylated alkyl and aryl 1,2-trans-1-thioglycosides was prepared by one step processes from peracylated 1,2-trans-related sugars by a procedure which involved the use of equimolar proportions of thiols together with boron trifluoride. A similar procedure was used to obtain benzoylated 1,2-cis-O-glucosides from penta-O-benzoyl-Beta-D-glucopyranose. Partial desulphurisation of acetylated glucosyl phenyl disulphide with tris(diethylamino)phosphine led to both phenyl tetra-O-acetyl-1-thio-alpha-D-glucopyranoside and the alpha, beta-linked thiotrehalose peracetate. Phenyl 1-thiohex-1-enopyranosid-3-ulose esters were obtained from the light induced reactions of N-bromosuccinimide with acetylated and benzoylated phenyl 1-thiogluco- and galacto-pyranosides; the acetylated 1-thioglycosides gave mixtures of 2-O-acetyl and 2-O-monobromoacetyl 1-enosid-3-uloses. Methyl hexuronate derivatives were brominated alpha to the carbonyl function by N-bromosuccinimide, and a new synthetic route to L-ascorbic acid has been proposed following the successful bromination of methyl tri-O-acetyl-2,6-anhydro-L-gulonate

Azetidine Analogues Nucleosidase And Phosphorylase Inhibitors

This invention relates to certain azetidine analogues of nucleosidase and nucleoside phosphorylase inhibitors, the use of these compounds as pharmaceuticals, pharmaceutical compositions containing the compounds, methods of treating certain diseases using the compounds, processes for preparing the compounds, and intermediates useful in the preparation of the compounds

German natural law

No abstract available