Dihydroisochinolinumlagerung, 25. Mitt. Untersuchungen der Stereochemie durch chemische Korrelation

Dihydroisoquinoline Rearrangement, XXV: Investigation of the Stereochemistry by Chemical Correlation The rearrangement of 1-benzyl-1,2-dihydroisoquinolines, which had proved to be intermolecular and stereoselective or even stereospecific in nature, was assumed to occur by a bimolecular concerted mechanism. If this hypothesis was correct, S-1 should rearrange via 3 to yield the iminium salt R-4. Investigation of the configurations of starting material and end product by chemical correlation showed, however, that S(-) 4 is obtained by rearrangement of S(+) 1. Accordingly the postulated mechanism cannot be correct.