Regiocontrolled Diels–-Alder reactions of 9-chloro-10-hydroxyanthracene-1,4-dione
Abstract
The title compound reacts with isoprene in the presence of aluminium chloride of boron trifluoride–ether to give the 2-methyl derivative of 6-chloro-11-hydroxy-14,4a, 12a-tetrahydronaphthacene-5,12-done;in the presence of boron triacetate, the 3-methyl isomer is the major product.