Gulono 3,6-anhydro

Anhydro-n-gulono- 3, 6-Anhydro-L-xylo-2-1, 4-laeton hexidosonsSure-l, 4-lacton... 

Anhydro-L-gulono-1,4-lactone (62) was prepared100 in 62% yield by the platinum-catalyzed oxidation of 1,4-anhydro-D-glucitol. Methyl 3,4,5-tri-0-acetyl-2,6-anhydro-L-gulonate (63, R = H) was obtained from D-glucuronic acid by way of the tetraacetate (63, R = OAc) and the thioglycoside101,102 (63, R = SPh) (76%), followed by reduction in the presence of Raney nickel to afford 63 (R= H) (68%). 

Another kind of intervention in the anhydrohexose aldose equilibrium has been described for l,6-anhydro-/3-D-gulopyranose. The action of 40% aqueous hydrogen bromide and bromine at 80° causes simultaneous hydrolysis and oxidation to D-gulono-1,4-lactone.122... 

A suspension of 2 g. dehydro-L-ascorbic acid phenylosazone in an ethanolic soln. of CuClg refluxed 15 min. 1.7 g. 3,6-anhydro-3-phenylazo-2-oxo-L-gulono-5-lactone phenylhydrazone. F. e., and mild oxidants such as FeClg, s. H. El Khadem and S. H. El Ashry, Soc. (C) 1968, 2251. 

Acid Derivatives.— 2,2 5,6-Di-0-isopropylidene-2-C-hydroxymethyl-L-gulono-1,4-lactone/ AT-(2-chloroethyl)-D-gluconamide (n.d.)/ 5-azido-5-deoxy-AriV-diethyl-l,2-0-isopropylidene-3-(9-methanesulphonyl-P-L-iodoruranuron-amide/ 3,6-anhydro-7-(4-bromobenzoyl)-2-deoxy-4,5-0-isopropylidene-D-ahro-heptononitrile/ sodium o-isoascorbate, and reductic acid (2,3-di-hydroxycycIopent-2-enone). . 

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