D 2633 (OTTO) Diethyl acetylenedicarboxylate, 98% Cas 762-21-0 - used as a protein cross-linker. It is also used in the synthesis of 3,4,5-trisubstituted 2(5H)-furanone derivatives, highly functionalized thiazolidinone derivatives, novel cyclic peroxide glucosides and 4,11-dimesitylbisanthene, soluble bisanthene derivative, via Diels-Alder reaction.