Determination of ring size

Determination of Ring Size Periodic Acid Cleavage of Sugars... 

The determination of ring size of the product 1 was based on the 1R carbonyl absorption at 1680 cm-1, characteristic of the ftve-membered-ring lactam. The stereochemistry was determined on the basis of mechanistic considerations, since the reaction proceeds via an anti addition. Moreover only one product was detected in the cyclization starting from cycloalkenyl derivatives, the co-fusion of the bicyclic system 2 was observed131, l32. 

Before we can go on to the pext aspect of the structure of D-(+)-glucose, determination of ring size, we must first learn a little more about the methylation of carbohydrates. 

Figure 34.13. Determination of ring size. Methylation of D>glucose, followed by hydrolysis.

Determination of Ring Size by Glycol Cleavage Periodate Ion as an Oxidant... 

The dialdehydes obtained in the periodate oxidation of glycosides and utilized for the determination of ring size (p. 32, 216), were also employed by Jackson and Hudson 94) for the configurational correlation of the anomeric carbons of aldohexopyranosides and aldopentopyranosides. The dialdehydes were oxidized to the dibasic acids and these were isolated as... 

A further paper on the determination of ring sizes of isopropylidene acetals means of the C-n.m.r. of the acetal carbon atoms has appeared. An improved synthesis of 1,2 5 6-di-O-isopropylidene-D-galactofuranose by means of the treatment of the enose (1) with borane in DMS, followed by alkaline hydrogen peroxide, has been described. ... 

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