A Facile Synthesis of 5-Hydroxy-6,6-dimethyl-6,7-dihydrobenzisoxazol-4(5H)-ones via Ionic Hydrogenation.

A facile synthesis of novel 5-hydroxy-6,6-dimethyl-6,7-dihydrobenzo[d]isoxazol-4(5H)-ones and 5-hydroxy-6,6-dimethyl-6,7-dihydrobenzo[c]isoxazol-4(5H)-ones starting from the corresponding 6,6-dimethyl-6,7-dihydrobenzisoxazol-4(5H)-ones was developed. The approach includes an oxidation of methylene group adjacent to carbonyl to ketone with selenium dioxide in acetic acid followed by regioselective reduction of the formed carbonyl to hydroxyl group with triethyl silane in trifluoroacetic acid. A series of 14 target compounds were prepared using developed method with yield of 50–87% in two steps. The synthesized α-hydroxy ketones were tested as potential antiproliferative agents against BT-474 breast carcinoma cell line, however at concentration of 50 µM they showed no negative effect on the growth of these cancer cells. [ABSTRACT FROM AUTHOR]