2(3H)-Furanone, 3-(triphenylphosphoranylidene)- 2(3H)-Furanone, dihydro-3-(triphenylphosphoranylidene)- (9CI) 2-(Triphenylphosphoranylidene)-gamma-butyrolactone 34932-07-5 BRN 1260939 NSC 100769 alpha-(Triphenylphosphoranylidene)-gamma-butyrolactone gamma-Butyrolactonylidene triphenyl phosphorane