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C-glycoside syntheses: Part I. Dendritic syntheses of hexose and aminohexose C-pyranosides from 2,6-anhydro-5,7-O-benzylidene-1-deoxy-1-nitro-D-guloheptitol (82). Part II. Henry condensation of nitroethane and nitropropane with 4,6-O-benzylidene-D-glucopyranose (81)

Author

Xiaojing Wang, University of the Pacific

Date of Award

1993

Document Type

Dissertation - Pacific Access Restricted

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Chemistry

First Advisor

Paul H. Gross

First Committee Member

Michael J. Minch

Second Committee Member

Patrick R. Jones

Third Committee Member

S. [?]

Fourth Committee Member

David Fries

Abstract

The di-O-acetyl derivative of 4,6-O-benzylidene-1-deoxy-1-nitromethyl-β-D-glucopyranose was reduced by a mixture of elemental iron and nickel in aqueous tetrahydrofuran under CO₂, with concurrent O → N acetyl migration to 1-acetamido-4-O-acetyl-2,6-anhydro-5,7-O-benzylidene-1-deoxy-D-glycero-D-guloheptitol. Its 2-O-mesyl derivative was converted by base into the D-manno-2,3-epoxide. The epoxide ring was opened by NH₃ to give the 3-amino-β-D-altropyranose derivative, which was subsequently N-benzoylated to 1-acetamido-2,6-anhydro-4-benzoylamino-5,7-O-benzylidene-1,4-dideoxy-D-glycero-D-glucoheptitol. Attempts to prepare 1-acetamido-2,6-anhydro-4-benzoylamino-5,7-O-benzylidene-1,4-dideoxy-3-methanesulfonyl-Dglycero-D-glucoheptitol gave spontaneously the D-allo-oxazoline derivative. However, a 3-O-mesyl derivative could be obtained by mesylation of 1,4-di-acetamido-2,6-anhydro-5,7-0-benzylidene-I,4-dideoxy-D-glycero-D-glucoheptitol. 2,6-Anhydro-5,7-O-benzylidene-1-deoxy-1-nitro-D-glycero-D-guloheptitol was reduced and N-acetylated to the acetamidomethyl derivative. 3,4-Di-O-mesylation of 1-acetamido-2,6-anhydro-5,7-O-benzylidene-1-deoxy-D-glycero-D-guloheptitol gave 1-acetamido-2,6-anhydro-5,7-O-benzylidene-1-deoxy-3,4-dimethanesulfonyl-D-glycero-D-guloheptitol, which reacted with methoxide to give the D-manno-2,3-epoxide, and mostly 2,6-anhydro-5,7-O-benzylidene-1-deoxy-D-glycero-D-gluco-heptitol [1,2,3, : 4',5',6']- 2'-methyl-2'-oxazine, presumably via a D-allo-2,3-epoxide.

The condensation of 4,6-O-benzylidene-D-glucopyranose with nitroethane gave 2,6-anhydro-1,3-O-benzylidene-7,8-dideoxy-7-nitro-D-threo-L-gulooctitol and its diastereomer, which was obtained by an acetylation-deacetylation procedure. 2,6-Anhydro-1,3-O-benzylidene-7,8-dideoxy-7-nitro-L-erythro-L-gulooctitol was reduced by a mixture of elemental Fe°/Ni° in aqueous FHF under CO₂ to 7-amino-2,6-anhydro-1,3-O-benzylidene-7,8-dideoxy-L-erythro-L-gulooctitol with retention of the 4,6-O-benzylidene blocking group. Acetylation of 2,6-anhydro-1,3-O-benzylidene-7,8-dideoxy-7-nitro-D-threo-L-gulooctitol produced an open chain compound. Cyclic product was not isolated. The oxime derivative, 4,5-di-O-acetyl-3,7-anhydro-6,8-O-benzylidene-1,2-dideoxy-2-oxime-D-glycero-D-guloheptitol, was separated as a byproduct from the acetylation. The condensation of nitropropane with 4,6-O-benzylidene-B-D-glucopyranose, followed by acetylation of the reaction solution, gave 4,5-di-O-acetyl-2,6-anhydro-1,3-O-benzylidene-7-nitro-7,8,9-trideoxy-D-threo-L-gulononitol and its diastereomer. Deacetylation of 4,5-di-O-acetyl-2,6-anhydro-1,3-O-benzylidene-7-nitro-7,8,9-trideoxy-D-threo-L-gulononitol gave 2,6-anhydro-1,3-O-benzylidene-7-nitro-7,8,9-trideoxy-D-threo-L-gulononitol, which could be reduced to the free amino compound by a mixture of elemental Fe°/Ni° in aqueous THF under CO₂.

Pages

126

Recommended Citation

Wang, Xiaojing. (1993). C-glycoside syntheses: Part I. Dendritic syntheses of hexose and aminohexose C-pyranosides from 2,6-anhydro-5,7-O-benzylidene-1-deoxy-1-nitro-D-guloheptitol (82). Part II. Henry condensation of nitroethane and nitropropane with 4,6-O-benzylidene-D-glucopyranose (81). University of the Pacific, Dissertation - Pacific Access Restricted. https://scholarlycommons.pacific.edu/uop_etds/2936