128990-41-0Relevant academic research and scientific papers
Efficient synthesis of L-galactose from D-galactose
Orii, Ryo,Izumi, Masayuki,Kajihara, Yasuhiro,Okamoto, Ryo
, p. 560 - 566 (2015)
Racemic protein crystallography is an emerging methodology to obtain high-resolution protein structures. Preparation of both a mirror image of protein and a mirror image of glycan is essential to apply the new methodology to glycoprotein. This article describes an efficient synthesis of L-galactose that is amirror image of D-galactose. The developed method takes only 6 steps from D-galactose without any chromatographic purification.
Synthesis of peracetylated C-1-deoxyalditol- and C-glycoside-dipyrranes via dithioacetal derivatives
Ló, Stephanie M.S.,Cunico, Juliana C.,Ducatti, Diogo R.B.,Orsato, Alexandre,Duarte, M. Eugênia R.,Barreira, Sandra M.W.,Noseda, Miguel D.,Gon?alves, Alan G.
supporting information, p. 1137 - 1140 (2013/05/08)
Dipyrranes bearing peracetylated mono- or disaccharidic C-1-deoxyalditol moieties were prepared from d-galactose, d-glucose, d-mannose, and lactose. A partially hydrolyzed polysaccharide (agarose) was also used as starting material for the synthesis of a disaccharide-containing C-glycoside dipyrrane. These compounds were synthesized as follows: the sugar starting materials were first submitted to a mercaptolysis-acetylation one-pot procedure (EtSH/HCl-Ac 2O/pyridine). The resulting peracetylated diethyl dithioacetals were converted into dipyrranes through carbonyl deprotection (H5IO 6, THF-Et2O) followed by TFA-catalyzed pyrrole condensation with yields up to 62%. Overall yields from sugar starting materials were up to 49%.
1,2;3,4-Di-O-isopropylidene-l-galactose synthesis from its d-enantiomer
Doboszewski, Bogdan,Herdewijn, Piet
experimental part, p. 2253 - 2256 (2012/05/20)
Easy procedure was devised to obtain di-O-isopropylidene-l-galactose from di-O-isopropylidene-d-galactose.
Synthesis of L-gulose, L-galactose, and their acetylated aldehydo forms from 6-S-phenyl-6-thio-D-hexoses
Gonzalez, Francisco Santoyo,Baer, Hans H.
, p. 33 - 47 (2007/10/02)
Methyl 6-S-phenyl-6-thio-α-D-glucopyranoside, prepared in high yield from methyl α-D-glucopyranoside by the action of diphenyl sulfide and tributylphosphine in pyridine, was converted into 6-S-phenyl-6-thio-D-glucitol pentaacetate (7) by sequential hydrolysis, borohydride reduction, and acetylation.Oxidation of 7 with 3-chloroperoxybenzoic acid gave the corresponding S-epimeric sulfoxides, which underwent Pummerer rearrangement to 1-epimeric L-gulose S-phenyl monothiohemiacetal hexaacetates.Boron trifluoride-catalyzed reaction of the latter with thiophenol gave theanalogues diphenyl dithioacetal, whereas base-catalyzed methanolysis led to free L-gulose.Treatment of 7 with N-chlorosuccinimide afforded 1-epimeric 1-chloro-1-S-phenyl-1-thio-L-gulitol pentaacetates, which were hydrolyzed to provide aldehydo-L-gulose pentaacetate.The same reaction sequences were performed with 6-S-phenyl-6-thio-D-galactose, synthesized in two steps from 1,2:3,4-di-O-isopropylidene-α-D-galactopyranose, furnishing ultimately L-galactose, its diphenyl dithioacetal pentaacetate, and aldehydo-L-galactose pentaacetate.Similar reaction sequences for the chain-terminal interchange of oxidation state in other ω-S-phenyl-ω-thioaldoses may prove useful for the preparation of less-common sugar derivatives.
1,6-Anhydrofuranoses, XI. - 1,6-Anhydro-α-L-idofuranose
Koell, Peter,John, Hans-Georg,Schulz, Juergen
, p. 613 - 625 (2007/10/02)
The title compound 13 is prepared on different routes from suitable benzyl derivatives with gluco-configuration.Preparations use the susceptibility of axial 5-O-benzyl groups in this compounds to selective hydrogenolysis, thus allowing subsequent inversion of configuration in this position from D-gluco to L-ido by an oxidation/reduction sequence.Only 0.08percent of 13 are found in the equilibrium mixture of idose in acidic medium.It is shown with 4-C-methyltalose as example, that the amount of 1,6-anhydrofuranoses in these equilibria rises significantly by changing the hydroxy groups in 4-position from secondary to tertiary ones.
