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US 4,283,340 AGranted
Ascorbic acid intermediates
AssigneePfizer Inc.
InventorThomas C. Crawford
Life of this patent
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Abstract
A synthetic route to ascorbic acid is provided in which a 3,5:4,6-protected derivative of gulonic acid is prepared from gulono-1,4-lactone. Oxidation of the derivative and hydrolysis of the resulting product affords 2-ketogulonic acid or ester thereof which can be readily converted to ascorbic acid by known methods.
Claims6
Methyl 3,5:4,6-di-O-benzylidene-L-gulonate.
Ethyl 3,5:4,6-di-O-benzylidene-L-gulonate.
Isopropyl 3,5:4,6-di-O-benzylidene-L-gulonate.
Ethyl 3,5:4,6-di-O-benzylidene-2-nitrato-L-gulonate.
Ethyl 3,5:4,6-di-O-benzylidene-L-xylo-hexulosanate.
Isopropyl 3,5:4,6-di-O-benzylidene-L-xylo-hexulosanate.
Dependencies are inferred from the claim text.