176976-54-8 2',2',5,7-Tetramethyl-6-oxospiro(1,3-diazaadamantane-2,4'-tetrahydropyrane) Spiro(1,3-diazatricyclo(3.3.1.1(sup 3,7))decane-2,4'-(4H)pyran)-6-one, tetrahydro-2',2',5,7-tetramethyl-