Korner method of absolute orientation

This work was actually carried out by Wilhelm K rner, of the University of Milan, and was the first example of the Korner method of absolute orientation.)... 

To determine the effect of a group on orientation is, in principle, quite simple the compound containing this group attached to benzene is allowed to undergo substitution and the product is analyzed for the proportions of the three isomers. Identification of each isomer as ortho, meta, or para generally involves comparison with an authentic sample of that isomer prepared by some other method from a compound whose structure is known. In the last analysis, of course, all these identifications go back to absolute determinations of the Korner type (Problem 10.8, p. 332). 

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