Glucopyranose 1,3,4,6 - tetra - 0 - acetyl - 2 - deoxy

RIC200 (JV-(S-Nitroso-JV-acetylpenicillamine)-2-amino-2-deoxy-1,3,4,6, tetra-O-acetyl-beta-D-glucopyranose)... 

Fluoroacetyl)ation and (trifluoroacetyl)ation of the amino groups provides a simple means of labelling amino sugars with the 19F nucleus. N-(Fluoroacetyl)ation occurs readily by treatment of, for example, l,3,4,6-tetra-0-acetyl-2-amino-2-deoxy-/3-D-glucopyranose with... 

A coupling constant (1.5 Hz) is observed between F-3e and that H-6 atom which resides for most of the time in the orientation antiparallel to the C-5-0-5 bond in l,2,4,6-tetra-0-acetyl-3-deoxy-3-fluoro-/3-D-glucopyranose (126), and it was suggested296 that the favored pathway for 19F- H coupling to occur over five bonds would approximate such... 

A few years later Goebel and Ugi formed a-aminoacid derivatives by the U-4CR with tetra-6)-aIkyl-l-glucopyranosylamines, 58, where any carboxylic acid component can participate. Lehnhoff and Ugi used the U-4CR with 1-amino-2-deoxy-2-Al-acetylamino-3,4,6-tri-6)-acetyl- 3-D-glucopyranose, 59, whose large variety of products could be formed stereoselectively in excellent yields. The desired selective cleavage of the auxiliary groups of these products was equally unefficient. 

This hypothesis would seem justified62 by the fact that the same reaction performed on the epimeric halide (manno configuration) (34) leads to a mixture containing 60% of the 3,3,4,6-tetraacetate of methyl 2-bromo-2-deoxy-a-D-arafcmo-hexopyranosid-3-ulose 3-hydrate (38) and 20% of l,3,4,6-tetra-0-acetyl-2-0-methyl-/8-D-glucopyranose... 

Migration of the ring-oxygen atom also occurred predominantly in the deamination of the tetra-O-acetyl derivatives of 2-amino-2-deoxy-a- and -/3-D-glucopyranose to give 3,4,6-tri-0-acetyl-2,5-anhydro-D-mannose (10), which is unstable and readily eliminates acetic acid to... 

Syntheses of 1,3,4,6-Tetra-O-acetyl-2-deoxy-2-halogeno- -D-glucopyranoses [Eq. (20) 6, 7, and 8]... 

Another synthetic sequence, leading to l,3,4,6-tetra-0-acetyl-2-deoxy-2-isothiocyanato-a-D-glucopyranose (26), proceeds by treatment of the corresponding l,3,4,6-tetra-0-acetyl-2-amino-2-deoxy-a-D-glucopyranose hydrochloride (25) with thiophosgene.39 A similar approach was employed... 

It is essential that isolation of the product be conducted rapidly and at 0° throughout, especially while the solution is acidic. All apparatus and solutions should be at hand before the reaction mixture is poured on ice. The product reacts fairly rapidly with water in the presence of an acid catalyst, undergoing acetyl migration to give the water-soluble 1,3,4,6-tetra-O-acetyl-2-amino-2-deoxy-a-D-glucopyranose hydrochloride. 

TETRA-0-ACETYL-2-DEOXY-a-D-GLUCOPYRANOSE (a-D-arablno-Hexopyranose, 2-deoxy-, letracetate)... 

Tetra-0-acetyl-2-deoxy-a-D-glucopyranose D-arabino-Hexopyranose, 2-deoxy-, tetraacetate, a- (8) a-D-arabino-Hexopyranose, 2-deoxy-, tetraacetate (9) (16750-06-4)... 

METHOXYCARBONYL-1,1,6-TRIMETHYL-1,4,4a,5,6,7,8,8a-OCTAHYDRO-2,3-BENZOPYRONE, an intramolecular Diels-Alder reaction is responsible for the diastereoselectivity. The stereoselective 1,4-functionalization of 1,3-dienes is exemplified by a two-step process leading to cis- and trans-1-ACETOXY-4-(DICARBOMETHOXYMETHYL)-2-CYCLOHEXENE. The effectiveness of a silyl hydride in providing a means for erythro-directed reduction of a p-keto amide is applied in a route to ERYTHRO-1 -(3-HYDROXY-2-METHYL-3-PHENYL-PROPANOYLJPIPERIDINE. This is followed by an asymmetric synthesis based on a chiral bicyclic lactam leading to (R)-4-ETHYL-4-ALLYL-2-CYCLOHEXEN-1-ONE. The stereoselectivity with which acetoxy migration can operate to an adjacent radical center is reflected in the one-step reaction that gives rise to 1,3,4,6-TETRA-O-ACETYL-2-DEOXY-a-D-GLUCOPYRANOSE. 

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