. "5-[(5-Methyl-2,4-dioxohexahydro-5-pyrimidinyl)methyl]-2,4(1H,3H)-pyrimidinedione" . . "5,6-Dihydro-5(\u03B1-thyminyl)thymine" . . . . . . . "5-Thyminyl-5,6-dihydrothymine" . "5,6-Dihydro-5(\u03B1-thyminyl)thymine" . . . . . .