Synthesis and Polymerization of Trimethyl Bicyclobutane-1,2,2-Tricarboxylate

✍ Scribed by H. K. Hall Jr.; Walter Fischer

• Publisher: John Wiley and Sons
• Year: 1977
• Tongue: German
• Weight: 342 KB
• Volume: 60
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19770600608

✦ Synopsis

Abstract

Trimethyl bicyclobutane‐1,2,2‐tricarboxylate (2) was synthesized by a facile five‐step route, beginning with the ferric chloride‐catalyzed addition of chloroform to methyl acrylate to give methyl 2,4,4‐trichlorobutyrate (3). Replacement of the 2‐chloro group by iodide was followed by displacement with dimethyl malonate anion to give trimethyl 4,4‐dichlorobutane‐1,1,2‐tricarboxylate (5a). Thermolysis of the corresponding sodium derivative 5b gave trimethyl cis, trans‐3‐chlorocyclobutane‐1,2,2‐tricarboxylate (6). Closure of the bicyclobutane ring to yield 2 was accomplished by potassium hydride in ether with methanol as catalyst.

Bicyclobutane 2 polymerized under free radical initiation with breakage only of the 1,3‐bond. The homopolymers, obtained in moderate yields, were of low molecular weight, probably owing to steric hindrance effects. Copolymerization occurred with vinyl monomers of varying polarity. The copolymers, obtained in moderate yields, had low molecular weights and consisted mostly of the vinyl comonomer units.