2,3,4,10-Tetrahydro-3-hydroxy-2,2,10-trimethyl-5H-pyrano(2,3-b)quinolin-5-one 5H-Pyrano(2,3-b)quinolin-5-one, 2,3,4,10-tetrahydro-3-hydroxy-2,2,10-trimethyl- 7688-58-6