2,5-Dihydrofuran 1708-29-8 1-Oxa-3-cyclopentene 3-Oxolene Furan, 2,5-dihydro- NSC60532 EINECS 216-957-4 NSC 60532 InChI=1/C4H6O/c1-2-4-5-3-1/h1-2H,3-4H 253170_ALDRICH