id paper:paper_09574166_v14_n17_p2579_RomeroZaliz
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spelling paper:paper_09574166_v14_n17_p2579_RomeroZaliz2023-06-08T15:56:28Z Straightforward synthesis of derivatives of D- and L-galactonic acids as precursors of stereoregular polymers 6 amino 6 deoxy 2,3,4,5 tetra o methyl dextro galactonic acid 6 amino 6 deoxy 2,3,4,5 tetra o methyl levo galactonic acid 6 azido 6 deoxy levo galactono 1,4 lactone acid azide bromine dimethyl sulfoxide ester ester derivative galactose lactone derivative levo galactonolactone methyl 6 azido 6 deoxy 2,3,4,5 tetra o methyl levo galactonate methyl group methyl iodide polymer potassium sodium hydroxide unclassified drug article bromination chemical analysis chemical structure methylation precursor priority journal reaction analysis structure analysis synthesis technique High yielding routes for the synthesis of selectively protected derivatives of D- and L-galactonic acids, having free OH or NH2 groups at the C-6 position, are reported. The successful direct per-O-methylation of galactonic acid derivatives from the corresponding galactono-1,4-lactones was developed as a key step of the sequence. For example, 6-azido-6-deoxy-L-galactono-1,4-lactone 16 was converted into the potassium salt and methylated (NaH, DMSO, MeI) to the methyl ester of the 2,3,4,5-tetra-O-methyl derivative 12. Compound 16 was readily prepared by bromination at C-6 of L-galactonolactone 1 and isopropylidenation; followed by substitution of bromine by azide and removal of the protecting groups. Hydrolysis of the methyl ester of 12 and hydrogenation of the azide led to the tetra-O-methyl derivative of the 6-amino acid 18 with 52% overall yield from 1. The same sequence applied to D-galactonolactone 19 led to the enantiomeric amino acid 25 with a 47% overall yield. © 2003 Elsevier Ltd. All rights reserved. 2003 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09574166_v14_n17_p2579_RomeroZaliz http://hdl.handle.net/20.500.12110/paper_09574166_v14_n17_p2579_RomeroZaliz
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic 6 amino 6 deoxy 2,3,4,5 tetra o methyl dextro galactonic acid
6 amino 6 deoxy 2,3,4,5 tetra o methyl levo galactonic acid
6 azido 6 deoxy levo galactono 1,4 lactone
acid
azide
bromine
dimethyl sulfoxide
ester
ester derivative
galactose
lactone derivative
levo galactonolactone
methyl 6 azido 6 deoxy 2,3,4,5 tetra o methyl levo galactonate
methyl group
methyl iodide
polymer
potassium
sodium hydroxide
unclassified drug
article
bromination
chemical analysis
chemical structure
methylation
precursor
priority journal
reaction analysis
structure analysis
synthesis
technique
spellingShingle 6 amino 6 deoxy 2,3,4,5 tetra o methyl dextro galactonic acid
6 amino 6 deoxy 2,3,4,5 tetra o methyl levo galactonic acid
6 azido 6 deoxy levo galactono 1,4 lactone
acid
azide
bromine
dimethyl sulfoxide
ester
ester derivative
galactose
lactone derivative
levo galactonolactone
methyl 6 azido 6 deoxy 2,3,4,5 tetra o methyl levo galactonate
methyl group
methyl iodide
polymer
potassium
sodium hydroxide
unclassified drug
article
bromination
chemical analysis
chemical structure
methylation
precursor
priority journal
reaction analysis
structure analysis
synthesis
technique
Straightforward synthesis of derivatives of D- and L-galactonic acids as precursors of stereoregular polymers
topic_facet 6 amino 6 deoxy 2,3,4,5 tetra o methyl dextro galactonic acid
6 amino 6 deoxy 2,3,4,5 tetra o methyl levo galactonic acid
6 azido 6 deoxy levo galactono 1,4 lactone
acid
azide
bromine
dimethyl sulfoxide
ester
ester derivative
galactose
lactone derivative
levo galactonolactone
methyl 6 azido 6 deoxy 2,3,4,5 tetra o methyl levo galactonate
methyl group
methyl iodide
polymer
potassium
sodium hydroxide
unclassified drug
article
bromination
chemical analysis
chemical structure
methylation
precursor
priority journal
reaction analysis
structure analysis
synthesis
technique
description High yielding routes for the synthesis of selectively protected derivatives of D- and L-galactonic acids, having free OH or NH2 groups at the C-6 position, are reported. The successful direct per-O-methylation of galactonic acid derivatives from the corresponding galactono-1,4-lactones was developed as a key step of the sequence. For example, 6-azido-6-deoxy-L-galactono-1,4-lactone 16 was converted into the potassium salt and methylated (NaH, DMSO, MeI) to the methyl ester of the 2,3,4,5-tetra-O-methyl derivative 12. Compound 16 was readily prepared by bromination at C-6 of L-galactonolactone 1 and isopropylidenation; followed by substitution of bromine by azide and removal of the protecting groups. Hydrolysis of the methyl ester of 12 and hydrogenation of the azide led to the tetra-O-methyl derivative of the 6-amino acid 18 with 52% overall yield from 1. The same sequence applied to D-galactonolactone 19 led to the enantiomeric amino acid 25 with a 47% overall yield. © 2003 Elsevier Ltd. All rights reserved.
title Straightforward synthesis of derivatives of D- and L-galactonic acids as precursors of stereoregular polymers
title_short Straightforward synthesis of derivatives of D- and L-galactonic acids as precursors of stereoregular polymers
title_full Straightforward synthesis of derivatives of D- and L-galactonic acids as precursors of stereoregular polymers
title_fullStr Straightforward synthesis of derivatives of D- and L-galactonic acids as precursors of stereoregular polymers
title_full_unstemmed Straightforward synthesis of derivatives of D- and L-galactonic acids as precursors of stereoregular polymers
title_sort straightforward synthesis of derivatives of d- and l-galactonic acids as precursors of stereoregular polymers
publishDate 2003
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_09574166_v14_n17_p2579_RomeroZaliz
http://hdl.handle.net/20.500.12110/paper_09574166_v14_n17_p2579_RomeroZaliz
_version_ 1768542653687791616