1.2- Di-O-methyl- -L-ascorbic acid

L-Ascorbyl palmitate L-Ascorbyl laurate D-Isoascorbyl laurate L-Ascorbic acid 2-sulfate 2,3-Di-O-methyl-l-ascorbic acid 3-Benzoyl-L-ascorbic acid 5,6-Isopropylidene-L-ascorbic acid 2,3 4,6-Di-0-isopropylidene-2-keto-L-gulonate 3-0- [ (Dimorpholino) phosphinate] -5,6-0-isopropyli-dene-L-ascorbate... 

Methylation of L-ascorbic acid with diazomethane has thrown some light on the tautomeric nature of the vitamin. The greater acidity of the C-3-OH enables it to be titrated with ethereal diazomethane to give 3-0-methylascorbic acid. This reaction, however, is also accompanied by the formation of a small quantity of 1-methyl- -L-ascorbic acid, presumably from a minor tautomer. Both of these compounds undergo further methylation with ethereal diazomethane to give 2,3-di-O-methyl-L-ascorbic acid and 1,2-di-O-methyl- -L-ascorbic acid respectively (Figure 4.9). 

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