Proton acid-catalysed transformations of estrogen derivatives: New results and some mechanistic aspects of the Kober colour reaction

Article abstract of DOI:10.1002/ardp.19943271007

The 3-O-methylated estrogen derivatives 1a-d and α-estradiol (1e) underwent sulfuric acid-catalysed transformations to furnish the steroids 2-6. The processes involved in the reaction sequence are regioselective sulfonation and, above all, the Wagner-Meerwein rearrangement of the methyl group at C-13. With the objective of obtaining further information on the course of the Kober colour reaction of estrogens, some UV/VIS and ESR spectroscopic investigations were also carried out.