Synthesis of polyhydroxy [n]-polyurethanes derived from a carbohydrate precursor

Polyhydroxy [n]-polyurethanes with chains formed by sugar-derived units have been synthesized. The enantiomerically pure monomeric precursor 1-amino-1-deoxy-2,3:4,5-di-O-isopropylidene-Dgalactitol (4) was prepared from D-galactono-1,4-lactone (1) by a three-step route. Acetonation of 1 with 2,2-dime...

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Publicado:	2009
Materias:	Activated monomers Crystalline polymers Ester groups High melting Hydroxyl groups Isocyanate monomers Isopropylidene Monomeric precursors Polymer chains Protecting group Reaction conditions SEM analysis Thermal stability Amides Amination Amines Chains Crystalline materials Esters Melting point Metabolism Monomers Polycondensation Polymer melts Polymers Polyurethanes Sugar (sucrose) Sugars Synthesis (chemical) Urea Zirconium Biological membranes
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00249297_v42_n21_p8112_Gomez http://hdl.handle.net/20.500.12110/paper_00249297_v42_n21_p8112_Gomez
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_00249297_v42_n21_p8112_Gomez
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spelling	paper:paper_00249297_v42_n21_p8112_Gomez2023-06-08T14:52:34Z Synthesis of polyhydroxy [n]-polyurethanes derived from a carbohydrate precursor Activated monomers Crystalline polymers Ester groups High melting Hydroxyl groups Isocyanate monomers Isopropylidene Monomeric precursors Polymer chains Protecting group Reaction conditions SEM analysis Thermal stability Amides Amination Amines Chains Crystalline materials Esters Melting point Metabolism Monomers Polycondensation Polymer melts Polymers Polyurethanes Sugar (sucrose) Sugars Synthesis (chemical) Urea Zirconium Biological membranes Polyhydroxy [n]-polyurethanes with chains formed by sugar-derived units have been synthesized. The enantiomerically pure monomeric precursor 1-amino-1-deoxy-2,3:4,5-di-O-isopropylidene-Dgalactitol (4) was prepared from D-galactono-1,4-lactone (1) by a three-step route. Acetonation of 1 with 2,2-dimethoxypropane gave methyl 2,3:4,5-di-O-isopropyldene-D-galactonate (2). The ester group of 2 was converted into the amide and reduced with LiAlH 4 to afford 4. This amino alditol was treated with di-tertbutyltricarbonate to produce the intermediate isocyanate derivative as activated monomer for the polymerization. The reaction conditions were adjusted to prevent the formation of urea linkages during the polycondensation. Thus, polymerization of the isocyanate monomer in THF and in the presence of Zr(acac)4 as catalyst afforded the linear [n]-polyurethane 6, which upon purification was practically free of urea linkages. Removal of the acetal protecting groups of 6 with 10:1 TFA-water, under conditions that did not produce hydrolysis of the polymer chain, led to the polyhydroxy [n]-polyurethane 8, having all the hydroxyl groups free. Polyurethanes 6 and 8 are examples of polyhydroxy [n]-polyurethanes entirely obtained from a sugar precursor. They were isolated as crystalline materials that exhibited high melting temperatures and thermal stability up to 230 °C. Accordingly, the SEM analysis of 6 and 8 revealed surfaces with morphologies characteristic of crystalline polymers. © 2009 American Chemical Society. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00249297_v42_n21_p8112_Gomez http://hdl.handle.net/20.500.12110/paper_00249297_v42_n21_p8112_Gomez
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Activated monomers Crystalline polymers Ester groups High melting Hydroxyl groups Isocyanate monomers Isopropylidene Monomeric precursors Polymer chains Protecting group Reaction conditions SEM analysis Thermal stability Amides Amination Amines Chains Crystalline materials Esters Melting point Metabolism Monomers Polycondensation Polymer melts Polymers Polyurethanes Sugar (sucrose) Sugars Synthesis (chemical) Urea Zirconium Biological membranes
spellingShingle	Activated monomers Crystalline polymers Ester groups High melting Hydroxyl groups Isocyanate monomers Isopropylidene Monomeric precursors Polymer chains Protecting group Reaction conditions SEM analysis Thermal stability Amides Amination Amines Chains Crystalline materials Esters Melting point Metabolism Monomers Polycondensation Polymer melts Polymers Polyurethanes Sugar (sucrose) Sugars Synthesis (chemical) Urea Zirconium Biological membranes Synthesis of polyhydroxy [n]-polyurethanes derived from a carbohydrate precursor
topic_facet	Activated monomers Crystalline polymers Ester groups High melting Hydroxyl groups Isocyanate monomers Isopropylidene Monomeric precursors Polymer chains Protecting group Reaction conditions SEM analysis Thermal stability Amides Amination Amines Chains Crystalline materials Esters Melting point Metabolism Monomers Polycondensation Polymer melts Polymers Polyurethanes Sugar (sucrose) Sugars Synthesis (chemical) Urea Zirconium Biological membranes
description	Polyhydroxy [n]-polyurethanes with chains formed by sugar-derived units have been synthesized. The enantiomerically pure monomeric precursor 1-amino-1-deoxy-2,3:4,5-di-O-isopropylidene-Dgalactitol (4) was prepared from D-galactono-1,4-lactone (1) by a three-step route. Acetonation of 1 with 2,2-dimethoxypropane gave methyl 2,3:4,5-di-O-isopropyldene-D-galactonate (2). The ester group of 2 was converted into the amide and reduced with LiAlH 4 to afford 4. This amino alditol was treated with di-tertbutyltricarbonate to produce the intermediate isocyanate derivative as activated monomer for the polymerization. The reaction conditions were adjusted to prevent the formation of urea linkages during the polycondensation. Thus, polymerization of the isocyanate monomer in THF and in the presence of Zr(acac)4 as catalyst afforded the linear [n]-polyurethane 6, which upon purification was practically free of urea linkages. Removal of the acetal protecting groups of 6 with 10:1 TFA-water, under conditions that did not produce hydrolysis of the polymer chain, led to the polyhydroxy [n]-polyurethane 8, having all the hydroxyl groups free. Polyurethanes 6 and 8 are examples of polyhydroxy [n]-polyurethanes entirely obtained from a sugar precursor. They were isolated as crystalline materials that exhibited high melting temperatures and thermal stability up to 230 °C. Accordingly, the SEM analysis of 6 and 8 revealed surfaces with morphologies characteristic of crystalline polymers. © 2009 American Chemical Society.
title	Synthesis of polyhydroxy [n]-polyurethanes derived from a carbohydrate precursor
title_short	Synthesis of polyhydroxy [n]-polyurethanes derived from a carbohydrate precursor
title_full	Synthesis of polyhydroxy [n]-polyurethanes derived from a carbohydrate precursor
title_fullStr	Synthesis of polyhydroxy [n]-polyurethanes derived from a carbohydrate precursor
title_full_unstemmed	Synthesis of polyhydroxy [n]-polyurethanes derived from a carbohydrate precursor
title_sort	synthesis of polyhydroxy [n]-polyurethanes derived from a carbohydrate precursor
publishDate	2009
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00249297_v42_n21_p8112_Gomez http://hdl.handle.net/20.500.12110/paper_00249297_v42_n21_p8112_Gomez
_version_	1768545361329127424

Synthesis of polyhydroxy [n]-polyurethanes derived from a carbohydrate precursor

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