Synonyms: 5,6-Dihydro-4H-pyran; DHP; DIHYDROPYRANE; 2,3-Dihydropyran; 3,4-Dihydropyran; 2H-3,4-Dihydropyran; 2H-Pyran,3,4-dihydro-; 3,4-Dihdro-2H-pyrane; 3,4-dihydro-2h-pyra; 3,4-Dihydro-2-pyran; delta(Sup2)-Dihydropyran; delta2-Dihydropyran; Pyran, dihydro-