Synthesis and radical ring-opening polymerization behavior of vinylcyclopropane bearing six-membered cyclic acetal moiety

✍ Scribed by Tadashi Okazaki; Fumio Sanda; Takeshi Endo

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 537 KB
• Volume: 34
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19960730)34:10<2029::aid-pola20>3.0.co;2-i

✦ Synopsis

Synthesis and radical ring-opening polymerization of vinylcyclopropane bearing six-membered cyclic acetal moiety, l-vinyl-4,8-dioxaspiro[ 2.5loctane ( l ) , were carried out. 1 was prepared by the reaction of l,l-dichloro-2-vinylcyclopropane and 1,3-propanediol in DMF in the presence of a base. Radical polymerization of 1 was carried out in the presence of an appropriate initiator ( 3 mol % vs. 1) at 60 and 12OOC in degassed sealed ampoules for 20 h. A colorless transparent viscous polymer was obtained by the isolation with preparative HPLC. The structure of poly( 1) was determined to consist of two 1,5-ring-opened units and a unit bearing no olefinic moiety. The difference of the activation energies for the ringopening reaction of the cyclopropane ring calculated by the molecular orbital method could explain the selectivity in the direction of the cleavage of the cyclopropane ring. Acid hydrolysis of poly( 1) afforded the corresponding polyketone in quantitative conversion.