70332-99-9

Basic information

• Product Name: 4,5-Dimethyl-1,4-cyclohexadien-1,2-dicarbonsaeure-di-tert-butylester
• Synonyms: 4,5-Dimethyl-1,4-cyclohexadien-1,2-dicarbonsaeure-di-tert-butylester
• CAS NO: 70332-99-9
• Molecular Weight: 308.418
• Mol File: 70332-99-9.mol
• Article Data: 1

Chemical Properties

• CAS DataBase Reference: 4,5-Dimethyl-1,4-cyclohexadien-1,2-dicarbonsaeure-di-tert-butylester(CAS DataBase Reference)
• NIST Chemistry Reference: 4,5-Dimethyl-1,4-cyclohexadien-1,2-dicarbonsaeure-di-tert-butylester(70332-99-9)
• EPA Substance Registry System: 4,5-Dimethyl-1,4-cyclohexadien-1,2-dicarbonsaeure-di-tert-butylester(70332-99-9)

Safety Data

• Hazardous Substances Data: 70332-99-9(Hazardous Substances Data)

Upstream product

• 513-81-5 2,3-dimethyl-buta-1,3-diene 
• 762-42-5 dimethyl acetylenedicarboxylate 
• 66086-33-7 Di-tert-butyl acetylenedicarboxylate 

Relevant articles and documents

Alkynes and Cumulenes, XII. The Application of Di-tert-butyl Acetylenedicarboxylate in Diels-Alder Additions

Di-tert-butyl acetylenedicarboxylate (1) may be added in good yields to the model dienes 1,3-butadiene (6a), 2-methyl-1,3-butadiene (6b), 2,3-dimethyl-1,3-butadiene (6c), furan (10), and 1,3-cyclohexadiene (19) to afford the Diels-Alder adducts 7a-c, 12 (E = CO2C(CH3)3), and 20, respectively.Under certain conditions the reaction with 10 also laeds to the four 2:1-adducts 13-16 (E = CO2C(CH3)3).Whereas the esters 7a-c are converted in quantitative yields to the corresponding anhydrides 8a-c by warming in the presence of catalytic amounts of p-toluenesulfonic acid or by heating in substance, the decomposition of 12 and 20 stops at the stage of the monoesters 17 and 21, respectively.Competition experiments show that 1 is approximately three times less reactive towards 6c than dimethyl acetylenedicarboxylate (11).It is shown that 1 is a useful dienophile for the preparation of "mixed" paracyclophanes of type 28.