172297-88-0

Upstream product

• 432038-84-1 methyl 2,3,6-tri-O-benzyl-4-O-(1H-imidazol-1-ylsulfonyl)-α-D-galactopyranoside 
• 288-94-8 1H-tetrazole 
• 88713-85-3 methyl 4-azido-2,3,6-tri-O-benzyl-4-deoxy-α-D-galactopyranoside 
• 121-45-9 phosphorous acid trimethyl ester 
• 19488-48-3 methyl 2,3,6-tri-O-benzyl-α-D-galactopyranoside 
• 7189-69-7 N,N`-sulfuryldiimidazole 
• 192637-12-0 methyl 2,3,6-tri-O-benzyl-4-O-triflyl-α-D-(4-2H)glucopyranoside 
• 184898-72-4 methyl 2,3,6-tri-O-benzyl-4-O-triflyl-α-D-(4-2H)galactopyranoside 
• 917-54-4 methyllithium 
• 112260-57-8 methyl 2,3,6-tri-O-benzyl-α-D-glucopyranoside 

Relevant academic research and scientific papers

α-Hydrogen Elimination in Some Carbohydrate Triflates

In some carbohydrate triflates, treatment with MeLi (or BuLi) in ether caused α-hydrogen elimination initially, then the resulting carbanion is stabilized to give either C-methyl(or butyl)-hydroxy derivatives or unsaturated products.

Steric course of some cyclopropanation reactions of L-threo-hex-4- enopyranosides

Completely protected 4-deoxy-α-L-threo-hex-4-enopyranosides 1c,d undergo the dichlorocarbene addition affording exclusively diastereomeric adducts 5c,d with the cyclopropane ring anti to the C-3 alkyloxy substituent, while the reaction with 3-unprotected derivatives 1a,b affords a mixture of syn and anti derivatives. Under the Simmons-Smith cyclopropanation adducts 2a-d with a syn stereochemistry are obtained. Starting from 5b, the cyclopropanated sugar 3b is obtained by reduction with LiAlH4, thus the two diastereomers 2b and 3b can be stereoselectively obtained through the two different pathways. For a useful comparison, 4-deoxy-β-L-threo-hex-4- enopyranoside 1e was also subjected to the above two cyclopropanation methods affording the expected cycloadduct 2e and a diastereomeric mixture of dichlorocycloadducts 4e and 5e (4e/5e=2.8:1).

A New reaction for the direct conversion of 4-azido-4-deoxy-D-galactoside into a 4-deoxy-D-erythro-hexos-3-ulose

A new one-step reaction has been developed for converting 4-azido-4-deoxy-D-galactoside into 4-deoxy-D-erythro-hexos-3-ulose by phosphoramidites and tetrazole. It is proposed that the new reaction proceeds via an intramolecular Staudinger reaction of the

An efficient and highly regioselective synthesis of 4-deoxy- and 2-acetamido-2,4-dideoxy-β-D-threo-hex-3-enopyranosides

The preparation of the previously undescribed class of 4-deoxy- and 2,4-dideoxy-2-acetamido-β-D-threo-hex-3-enopyranosides was accomplished with a very high yield and a complete regioselectivity by means of a simultaneous activation-elimination process of

Reactions of some 2- and 4-O-triflylglycopyranosides with MeLi, t-BuOK, and pyridine

As an extension of our previous work on secondary triflates of carbohydrates [El Nemr, A.; Tsuchiya, T. Tetrahedron Lett. 1995, 36, 7665-7668. El Nemr, A.; Tsuchiya, T.; Kobayashi, Y. Carbohydr. Res. 1996, 293, 31-59. El Nemr, A.; Tsuchiya, T. Carbohydr. Res. 1997, 301, 77-87. El Nemr, A.; Tsuchiya, T. Carbohydr. Res. 1997, 303, 267-281], the reaction modes of several methyl 2- and 4-O-triflyl-D-glycopyranosides with MeLi (strong base), t-BuOK (moderately strong base), and pyridine (weak base) have been studied. This paper describes the reactions of 3-O-benzyl-4,6-O-benzylidene-2-O-triflyl-D-gluco and -mannopyranosides with MeLi to give mainly the corresponding 2-C-methyl derivatives through α-elimination, with t-BuOK to give either the 2,3-unsaturated compounds through β-elimination or detriflyl 2-ols, and with hot pyridine to give the corresponding 2-pyridinium salts with inversion (except for the 2-O-triflyl-α-D-mannopyranoside (8)). 2,3,6-Tri-O-benzyl-4-O-triflyl-α-D-gluco and -mannopyranosides were also examined similarly.

α-Hydrogen elimination in some 3- and 4-triflates of α-D- glycopyranosides

In previous papers [A. El Nemr and T. Tsuchiya, Tetrahedron Lett., 36 (1995) 7665-7668; A. El Nemr, T. Tsuchiya, and Y. Kobayashi, Carbohydr. Res., 293 (1996) 31-59] we reported new reactions that occur when some carbohydrate triflates are treated with MeLi (or BuLi) in ether, giving C-methyl (or butyl) or unsaturated compounds. Both reactions may be explained by α-hydrogen elimination in the triflates. This paper is an extension of the previous work and describes the mechanism of unsaturation of some 3- or 4-triflylates of α-D-glycopyranosides. By using deuterated analogs, it was found that methyl 2-O-benzyl-4,6-O-benzylidene-3-O-triflyl-α-D-glucopyranoside gives the 2,3- and 3,4-unsaturated compounds through a-hydrogen elimination, and the corresponding allopyranoside gives the 2,3-unsaturated compound through α- and β- (for 14) and α-hydrogen eliminations (for 19). Carbene formation is proposed as the key intermediate for the former eliminations, and a 1 → 2 proton-shift is proposed as the key reaction for the latter.