Hydroxyl groups periodate

The Malaprade reaction is the basis of the most important analytical application of periodate the determination of a-diols and a-carbonyl alcohols. If two adjacent carbon atoms have hydroxyl groups, periodate causes a cleavage of the carbon-carbon bond, with the formation of carbonyl groups ... 

The polyhydric alcohols of Solubility Group II are liquids of relatively high boiling point and may be detected inter alia by the reactions already described for Alcohols (see 6). Compounds containing two hydroxyl groups attached to adjacent carbon atoms (1 2-glyeols), a-hydroxy aldehydes and ketones, and 1 2-diketones may be identified by the periodic acid test, given in reaction 9. 

Periodic acid has a selective oxidising action upon compounds having two hydroxyl groups or a hydroxyl and an amino group attached to adjacent carbon atoms and is characterised by the cleavage of the carbon - carbon bond (Malaprade reaction) ... 

Cyclic diols give dicarbonyl compounds The reactions are faster when the hydroxyl groups are cis than when they are trans but both stereoisomers are oxidized by periodic acid... 

When three contiguous carbons bear hydroxyl groups two moles of periodate is consumed per mole of carbohydrate and the central carbon is oxidized to a molecule of formic acid... 

Example Brady investigated classical dynamics of a-d-glucose in water.In this simulation, 207 water molecules surrounded one a-d-glucose. The system was in a cubic box with periodic boundary conditions. During the simulation, several hydroxyl group transitions occurred. These transitions are normally unlikely with an in vacuo simulation. 

Somewhat milder oxidative conditions lead to loss of but one carbon. Periodic acid cleavage of the side chain in 65, leads to the so-called etio acid (66). Reaction with propionic anhydride leads to acylation of the 17-hydroxyl group (67). Possibilities for neighboring group participation severely limit the methods available for activating the acid for esterification. Best results seemed to have been obtained by use of a mixed anhydride from treatment with diphenyl chloro-... 

It is, in fact, interesting to note that the latter cyclohexanepentol, which has four adjacent cis-hydroxyl groups, reacts slowly with periodate. Perhaps further light will be thrown on this problem when the results of periodate oxidations of dl-1, 2, 3, 5/4-cyclohexanepentol (36), 1, 2, 4, 5/3-cyclohexanepentol (37), and (1 d)-1, 2, 3/4, 5-cyclohexanepentol (38) will be available. 

Most methods of testing bond type involve the motion of nuclei. The chemical method, such as substitution at positions adjacent to a hydroxyl group in testing for double-bond character, as used in the Mills-Nixon studies, is one of these. This method gives only the resultant bond type over the period required for the reaction to take place. Since this period is much longer than that of ordinary electronic resonance, the chemical method cannot be used in general to test for the constituent structures of a resonating molecule. Only in case that the resonance frequency is very small (less than the frequencies of nuclear vibration) can the usual methods be applied to test for the constituent structures and in this case the boundary between resonance and tautomerism is approached or passed. 

Hill, J.-R., Freeman, C. M., Delley, B., 1999, Bridging Hydroxyl Groups in Faujasite Periodic vs Cluster Density Functional Calculations , J. Phys. Chem. A, 103, 3772. 

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