منتديات لغاتى التعليمية

السلام عليكم ورحمة الله وبركاته
يمكن ترجمة هذا النص الى العربيه الله يعطيكم العافيه
Condensation of L-fhreo-2,3-hexodiulosono-1,6lactone (1) with 2 mol of onitrophenylhydrazine
gave the bis(o-nitrophenylhydrazone) 2, oxidation of which
with cupric chloride afforded 3,6-anhydro-3-(o-nitrophenylazo)-L-xylo-2-
hexulosono-1,4-lactone 2-(o-nitrophenylhydrazone). Controlled reaction of 1 with
o-nitrophenylhydrazine gave the 2-(o-nitrophenylhydrazone) 8, which underwent
dehydrative acetylation to yield 4-(2-acetoxyethylidene)-4-hydroxy-2,3-dioxobutyro-
1,4-lactone 2-(o-nitrophenylhydrazone). The reaction of 8 with phenyl- and
benzoyl-hydrazine afforded the mixed bis(hydrazones) 10 and 11. Oxidative cyclisation
of 10 with cupric chloride gave 3,6-anhydro-3-phenylazo-L-xylo-2-
hexulosono-1,Clactone 2-(o-nitrophenylhydrazone). The reaction of 8 with
methylhydrazine yielded the expected mixed bis(hydrazone) 19, which was dehydrated
during the acetylation and gave 4-(2-acetoxyethylidene)-4-hydroxy-2,3-dioxobutyro-
1,4-lactone 3-(N-acetylmethylhydrazone) 2-(o-nitrophenylhydrazone).
The condensation of 8 with hydroxylamine and semicarbazide was also studied.
INTRODUCTION
r_-three-2,3-Hexodiulosono-1,6lactone (1), obtained by the oxidation of
vitamin C, is a precursor for nitrogen heterocycles. Reaction of 1 with ophenylenediamine
or its derivatives gave quinoxaline+* and with semicarbazide,
followed by rearrangement, afforded the pyrazole derivatives314 which had biological
activity5-8. The mono- or bis-(phenylhydrazones) of 1 offer routes to various
nitrogen heterocycles9-15. We now report on the mono- and bis-(o-nitrophenylhydrazones)
of 1 and their oxidative cyclisation.
,3-hexodiulosono-1,6lactone 2-(o-nitrophenylhydrazone 3-oxime (12) and L-threo-
2,3-hexodiulosono-1,4-lactone 2-(o-nitrophenylhydrazone) 3-semicarbazone (13),
respectively.
In contrast to the phenyl analogue, the reaction of 8 with methylhydrazine
afforded the expected L-three-2,3-hexodiulosono-1,Clactone 3-methylhydrazone 2-
(o-nitrophenylh y d razone) (19), which had i.r. bands at 1730 (lactone C=O), 1610
(C=N), and 3280 and 3425 cm-’ (=NH and OH). The mass spectrum of 19 contained