Oxidation method using 5-linked directly

The method (scheme 1) was targeted to the utilization of readily available carbohydrate sources such as lactose, maltose starch and maltodextrins. It was applicable largely to the preparation of the (S)-acid 1 and the lactone 2 since naturally occurring hexoses have almost exclusively the D-configuration and the C5 carbon becomes the chiral center in the dihydroxy acid. More recently, direct access to the (R)-isomers 4 and 5 was made possible by the development of a similar oxidation method using 5-linked pentoses as the starting compounds... 

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