12-HYDROXYSTEARIC ACID 4-Hydroxycinnamic acid Diethyl acetylenedicarboxylate Acetylenedicarboxylic acid DI-TERT-BUTYL ACETYLENEDICARBOXYLATE BIS(TRI-N-BUTYLTIN)ACETYLENEDICARBOXYLATE BIS(TRIMETHYLSILYL)ACETYLENEDICARBOXYLATE 3-(1-HYDROXYCYCLOHEXYL)-2-PROPYNOIC ACID 4-HYDROXY-4-METHYL-PENT-2-YNOIC ACID