Synthesis of furanoid and pyranoid derivatives of 6-deoxy-4-thio-D-galactose
The synthesis of pyranoid and furanoid derivatives of 6-deoxy-4-thio-D-galactose from methyl α-D-glucopyranoside (1) is described. A key intermediate for the synthesis, methyl 2,3-di-O-benzoyl-6-deoxy-4-thio-α-D-galactopyranoside (15) was prepared by different approaches from 1. Regioselectivity for...
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| Autores principales: | , , |
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| Publicado: |
1990
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00404020_v46_n4_p1131_Cicero http://hdl.handle.net/20.500.12110/paper_00404020_v46_n4_p1131_Cicero |
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| Sumario: | The synthesis of pyranoid and furanoid derivatives of 6-deoxy-4-thio-D-galactose from methyl α-D-glucopyranoside (1) is described. A key intermediate for the synthesis, methyl 2,3-di-O-benzoyl-6-deoxy-4-thio-α-D-galactopyranoside (15) was prepared by different approaches from 1. Regioselectivity for the protection or modification of the hydroxyl groups of 1 or its derivatives was achieved by employing various reagents. The thiol group at C-4 was introduced by nucleophilic substitution of a tosylate by thiocyanate followed by reduction or alkaline methanolysis of the thiocyano group. A by-product of the latter reaction was characterized as a monothiolcarbonate derivative (17), whose conformation was studied by molecular mechanics calculations. Acetolysis of methyl 6-deoxy-4-thio-α-D-galactopyranoside (16) afforded ring sulfur containing derivatives of 6-deoxy-4-thio-D-galactofuranose, which are described for the first time. © 1990. |
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