77321-39-2

Basic information

• Product Name: Tetramethyl 1-(p-Methoxyphenyl)-2,2,3,3-cyclobutanetetracarboxylate
• CAS NO: 77321-39-2
• Molecular Weight: 394.378
• Mol File: 77321-39-2.mol
• Article Data: 1

Chemical Properties

• CAS DataBase Reference: Tetramethyl 1-(p-Methoxyphenyl)-2,2,3,3-cyclobutanetetracarboxylate(CAS DataBase Reference)
• NIST Chemistry Reference: Tetramethyl 1-(p-Methoxyphenyl)-2,2,3,3-cyclobutanetetracarboxylate(77321-39-2)
• EPA Substance Registry System: Tetramethyl 1-(p-Methoxyphenyl)-2,2,3,3-cyclobutanetetracarboxylate(77321-39-2)

Safety Data

• Hazardous Substances Data: 77321-39-2(Hazardous Substances Data)

Upstream product

• 637-69-4 4-Methoxystyrene 
• 1733-15-9 Tetramethyl ethylenetetracarboxylate 

Relevant articles and documents

Trapping Tetramethylene Biradical Intermediates in Cycloaddition Reactions of p-Methoxystyrene by Vinyl Copolymerization Reactions

Tetramethylene biradical intermediates in cycloaddition reactions of p-methoxystyrene (1) with trimethyl ethylenetricarboxylate (2) at 70 - 116 deg C and dimethyl cyanofumarate (10) at 28 deg C were detected through the formation of aternating 1:1 copolymers 5 and 11, identical with those formed by deliberate free-radical-initiated copolymerizations of these monomers.The rates were insensitive to solvent polarity.Free-radical inhibitors supressed copolymerization and led instead to cycloadducts, dihydropyrans 3 and 12, respectively, pointing to common intermediates incopolymerization and cycloaddition.Heating the kinetically favored dihydropyran 3 isomerized it to 1-butene 4.Vacuum distillation of 3 gave 1 and 2, while similar treatment of 12 gave copolymer by cycloreversion and spontaneous copolymerization.An ion-radical mechanism was excluded because deliberate generation of 1+. in presence of 2 gave cyclodimer 8 or homopolymer 7.Reaction of 1 with tetramethyl ethylenetetracarboxylate (14), which cannot copolymerize, led to cyclobutane 15 and traces of homopolymer 7 (some zwitterion character).The reactivity sequence 10 > 2 > 14 is dictated largely by resonance stabilization of and steric hindrance to tetramethylene formation.Consideration of the conformations available to tetramethylenes 16 - 18 provides a reasonable explanation of the results.