T. Goto, M. Konno, M. Saito
Apr 15, 1989
Citations
1
Influential Citations
15
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
6-Substituted and unsubstituted 6,7-dihydro-7-hydroxy-5H-pyrrolo[3,4-b]pyridin-5-ones were predominantly obtained in excellent yield by the reduction of the corresponding 5,7-diones with sodium borohydride in the presence of Mg ion at 0 °C. The highly regioselective production of the 7-hydroxy lactam in preference to the 5-hydroxy isomer was reasonably interpreted in terms of a chelate complex formation between the dione and Mg ion. The regioisomeric assignment was achieved by the transformation of the 7-hydroxy lactam to 2-(hydroxymethyl)-3-pyridinecarboxamides which could be converted to the known azaphthalide, furo[3,4-b]pyridin-5(7H)-one. Furthermore, the high chemoselectivity was found to be retained below 0 °C to give the partial reduction product, hydroxy lactam, exclusively.