189758-77-8

Upstream product

• 175844-98-1 methyl 3,4-di-O-benzyl-2,6-dideoxy-6-iodo-α-D-glucopyranoside 
• 6087-40-7 (2R,3S,4R,6S)-3,4-diacetoxy-2-(acetoxymethyl)-6-methoxytetrahydro-2H-pyran 
• 69617-72-7 (3S,4S,5R,1'S)-3-bromo-5-(2'-bromo-1'-hydroxy)ethyl-4,5-dihydro-4-hydroxy-2-(3H)-furanone 
• 189758-74-5 (2S,3S,4R,6S)-2-Bromomethyl-6-methoxy-tetrahydro-pyran-3,4-diol 
• 122204-66-4 methyl 2,6-dibromo-2,6-dideoxy-α-D-mannopyranoside 
• 81927-55-1 O-benzyl 2,2,2-trichloroacetimidate 
• 6752-48-3 methyl 4,6-O-benzylidene-2-deoxy-α-D-glucopyranoside 
• 13145-22-7 methyl 2-deoxy-α-D-glucopyranoside 
• 119943-96-3 Methyl 3-O-benzyl-4,6-O-benzylidene-2-deoxy-α-D-arabino-hexopyranoside 
• 145149-85-5 Methyl 3,4-di-O-benzyl-2-deoxy-α-D-arabino-hexopyranoside 
• 189758-76-7 (2S,3S,4R,6S)-3,4-Bis-benzyloxy-2-bromomethyl-6-methoxy-tetrahydro-pyran 

Downstream Products

• 506423-04-7 C₂₀H₂₂O₄ 
• 544673-43-0 C₂₀H₂₂O₄ 
• 189758-78-9 GS 416 
• 6272-38-4 O-benzylcatechol 

Relevant academic research and scientific papers

Vinyl Grignard-Mediated Stereoselective Carbocyclization of Lactone Acetals

A novel Ferrier-type carbocyclization is reported. It involves a carbohydrate-derived lactone acetal synthesized from methyl α-d-glucopyranoside, which upon treatment with excess vinylmagnesium bromide provides a highly substituted carbocyclic product as a single stereoisomer. The yield is greatly increased when N,N,N′,N′-tetramethylethylenediamine is added to the reaction mixture. Optimized reaction conditions have been applied to lactone acetals derived from other carbohydrates. Based on the obtained results, a possible reaction mechanism has been proposed. Furthermore, scalability of the reaction up to 15 g scale and derivatization of the carbocyclic product has been demonstrated, including the formation of a rare trans-bicyclo[4.3.0]nonene scaffold via a ring-closing metathesis. The structure of this and all carbocyclic products were confirmed by X-ray crystallographic analysis.

Synthesis of a-ring synthon of 19-nor-1alpha,25-dihydroxyvitamin D3 from (D)-glucose

The present invention provides a method for the synthesis of an A-ring synthon phosphine oxide used in the preparation of 19-nor vitamin D compounds, and to novel synthetic intermediates formed during the synthesis. The new method prepares the phosphine oxide from (D)-glucose.

Novel synthesis of 2-substituted 19-norvitamin D A-ring phosphine oxide from D-glucose as a building block

19-Norvitamin D A-ring phosphine oxide 5 was synthesized by a new sequence mode starting from D-glucose as a chiral template. Transformation of the pyranoside ring into the A-ring carbocycle was achieved by the Pd-catalyzed Ferrier rearrangement. The phosphine oxide 5 was obtained in an 18% overall yield by this novel cost-effective method.

Synthesis of the 2-deoxyisomaltose analogue of acarbose by an improved route to chiral valieneamines

A 2-deoxyisomaltose analogue of acarbose was stereoselectively synthesised in 11 steps with a total yield of 7% starting from 2,6-dibromo-2,6-dideoxy-D-mannono-1,4-lactone (6). The latter was reduced to the lactol, converted to the methyl glycoside (7) and hydrogenated to the 6-bromo-2,6-dideoxyglycoside (8). Benzylation of the hydroxy groups, elimination of bromine to a 5-ene and Ferrier carbocyclisation gave (2S,3R)-2,3-bisbenzyloxycyclohex-5-enone (12). 1,2-addition of benzyloxymethyl lithium at -110 C gave a 6:1 mixture of tertiary alcohols 13; the (1S) isomer was the major one. Reaction with trichloroacetyl isocyanate gave a carbamate 19, which, when dehydrated to the cyanate, spontaneously underwent [1,3] sigmatropic rearrangement to an isocyanate, which on addition of methanol gave the methylcarbamate 20. Basic hydrolysis of this compound gave (2R,3R,5R)-5-amino-1-benzyloxy-methyl-2,3-bis(benzyloxy)cyclohex-6-ene (22), which could be deprotected to 2-deoxyvalieneamine (5). Reaction with 2-azidoethyl 2,3,4-tri-O-benzyl-6-O-triflyl-α-D-glucopyranoside (34) gave the secondary amine 35, which was completely de-O-protected with sodium in ammonia to give 6-deoxy-6-((1R,3R,4R)-3,4-dihydroxy-5-hydroxymethylcyclohex-5-enylamino)-D- glucose (4), the 2-deoxyisomaltose analogue of acarbose.