2H-Pyran-2-carboxylic acid, tetrahydro-6-hydroxy-, .gamma.-lactone 5257-20-5 6,8-Dioxabicyclo[3.2.1]octan-7-one 6-Hydroxytetrahydropyran-2-carboxylic acid lactone NSC55666 Pyran-2-carboxylic acid, tetrahydro-6-hydroxy-, .gamma.-lactone WLN: T56 A AO COVTJ