4132-24-5

Upstream product

• 108-24-7 acetic anhydride 
• 95118-60-8 acetyl 2,3,4-tri-O-acetyl-6-O-tosyl-α/β-D-galactopyranose 
• 81969-64-4 1,6-Anhydro-α-L-idohexofuranose 
• 97234-14-5 pentabromophenyl 2,3,4,6-tetra-O-acetyl-β-D-galactopyranoside 
• 121363-55-1 2,3,4-Tri-O-acetyl-6-O-p-toluenesulfonyl-D-galactopyranose 
• 67307-86-2 2-O-(benzoyl)-1,6-anhydro-3,4-dideoxy-β-D-erythro-hex-3-enopyranose 
• 644-76-8 1,6-anhydro-β-D-galactopyranose 
• 4163-60-4 β-D-galactose peracetate 
• 3068-32-4 1-bromo-1-deoxy-2,3,4,6-tetra-O-acetyl-a-D-galactopyranoside 

Downstream Products

• 644-76-8 1,6-anhydro-β-D-galactopyranose 

Relevant academic research and scientific papers

1,6-Anhydro-1-thio-β-D-glucopyranose (thiolevoglucosan) and the corresponding sulfoxides and sulfone

Starting 1,2,3,4-tetra-O-acetyl-6-O-tosyl-β-D-glucopyranose (3) was converted into 2,3,4-tri-O-acetyl-1-thio-6-O-tosyl-β-D-glucopyranose (6) via intermediate glycosyl bromide 4 and S-thiouronium salt 5. Treatment of compound 6 with sodium methoxide gave 1,6-anhydro-1-thio-β-D-glucopyranose (thiolevoglucosan 2a). The isomeric sulfoxides 7 and 8 were prepared by selective oxidation of thiolevoglucosan 2a with hydrogen peroxide or 3-chloroperoxybenzoic acid. The structure of new compounds was confirmed by 1H and 13C NMR spectroscopy or by X-ray analysis; magnetic anisotropy of the sulfinyl and sulfonyl group has been discussed.

A practical large-scale access to 1,6-anhydro-β-D-hexopyranoses by a solid-supported solvent-free microwave-assisted procedure

Microwave irradiation of 6-O-tosyl or 2,6-di-O-tosyl peracetylated hexopyranoses absorbed on basic alumina in a dry medium afforded the corresponding 1,6-anhydro-β-D-hexopyranoses. A direct access to 1,6:3,4-dianhydro-β-D-altropyranose (16) from D-glucose is also described.

SYNTHESIS OF D-ALLOSAN FROM LEVOGLUCOSENONE

The stereoselective reduction and cis-dihydroxylation of levoglucosenone (1,6-anhydro-3,4-dideoxy-β-D-glycero-hex-3-enopyranos-2-ulose), gave D-allosan (1,6-anhydro-β-D-allopyranose) in high yield.

Method of preparing levoglucosenone

Levoglucosenone is prepared by reaction sequence using 1,6-anhydro-β-D-galactopyranose as a starting material. First, the starting material is reacted with ortho formate, obtaining an ortho ester of said starting material. Then, the ortho ester is placed under the conditions for a reductive elimination reaction of the ortho formate part of said ortho ester, thereby converting said ortho ester to a 1,6-anhydro-3,4-dideoxy derivative. The dideoxy derivative is placed under the conditions for oxidation of the hydroxy group of said dideoxy derivative, thereby forming levoglucosenone.

Synthesis of Levoglucosenone

Levoglucosenone was synthesized from D-galactose via reductive decarboxylation as a key reaction.Among the catalysts used for the key reaction, hydrous zirconium oxide was found to have the best activity.

A Mild Procedure for the Preparation of 1,6-Anhydro-β-D-hexopyranoses and Derivatives

Treatment of reducing 6-O-tosyl-D-glucopyranoses 1 with 1,8-diazabicycloundec-7-ene (DBU) afforded the corresponding 1,6-anhydro-β-D-hexopyranoses 2 in high yields.Reaction was also performed on partly acetylated tosylates of carbohydrates.

Mild procedures for the synthesis of 1,6-anhydroaldohexopyranoses

Penta-O-acetyl-β-D-galactopyranoside was converted in two steps into pentabromophenyl-1,2,3,4-tetra-O-acetyl-β-D-galactopyranoside.Short treatment of the latter with tetra-n-butylammonium hydroxide at 20 deg C, followed by acetylation, afforded crystalline 2,3,4-tri-O-acetyl-1,6-anhydro-β-D-galactopyranose.The same procedure could also be applied to the synthesis of the per-O-acetates of 1,6-anhydro-β-cellociose and 1,6-anhydro-β-D-glucopyranose. 2,3,4-Tri-O-acetyl-1,6-anhydro-β-D-glucopyranose could also be obtained in a one-flask procedure by selective tosylation of D-glucose at the primary hydroxyl group, followed by treatment with base and subsequent acetylation.

AMINE-CATALYZED TRANSFORMATION OF ENOLIC NONENZYMIC BROWNING PRODUCTS, ISOMALTOL GLYCOPYRANOSIDES INTO 1,6-ANHYDRO-β-D-HEXOPYRANOSES

The nonenzymic browning products, isomaltol D-galacto- and D-glucopyranosides, are transformed by 5:1 (v/v) triethylamine-pyrrolidine into 1,6-anhydro-β-D-galactopyranose (41percent) and 1,6-anhydro-β-D-glucopyranose (3percent), respectively.The amines, designed to simulate the amino functionality in proteins, peptides, and ammonia (eliminated by decomposition of amino acids, proteins, and peptides) relative to nonenzymic browning during the baking process, catalyzed the transformations through the production of alkoxide ions formed from deprotonation of the ring hydroxyl groups in 1 : 1 (v/v) aqueous ethanol.

1,6-Anhydrofuranoses, XI. - 1,6-Anhydro-α-L-idofuranose

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.