Synthesis and ring-opening polymerization of bicyclic lactones containing a tetrahydropyran ring. 2,6-Dioxabicyclo[2.2.2]octan-3-one

Synthesis and ring opening polymerization of bicyclic lactones containing a tetrahydropyran ring. 2,5-Dioxabicyclo[2.2.2]octan-3-one

“…In accordance with the poor cationic polymerizability, 3 was not hydrolyzed to a detectable extent, whereas 1, 6,8-dioxabicyclo-[3.2.1]octan-7-one (8), and e-caprolactone as a reference compound were hydrolyzed under the identical conditions to give first-order rate constants of 5.6 X 10"5, 1.6 X 10"5, and 0.4 X 10"5 s"\ respectively. These data are in conformity with the high reactivity in cationic polymerization of 1 The bicyclic lactone 3 was polymerized with anionic and coordination initiators such as butyllithium, lithium benzophenone ketyl, and tetraisopropyl ti tanate. However, the yields and number-average molecular weights of the polymers were quite low.…”

“…The solution was filtered and the solvent was removed by rotary evaporation. The oily residue was distilled under reduced pressure: yield 135.2 g (87%); bp 75-80 °C (8 mmHg); IR (neat) 3060 (y-c-h), 1760 (^c-o)> 1650 (roc), 1200 (vc-o-cX 1080 (rc-o-c) cm NMR (CDC13) 6.42 (d, J = 6.2 Hz, 1 , H-6), 4.76 (m, 1 H, H-5), 4.45 (m, 1 , H-2), 4.24 (q, J = 7.2 Hz, 2 H, Ctf2CH3), 1.9-2.2 (m, 4 , 2H-3 and 2H-4), 1.30 (t, J = 7.2 Hz, 3 H, CH2CH3); 13C NMR (CDClg) 170.96 (C=0), 142.63 (C-6), 100.70 (C-5), 73.12 (C-2), 61.06 (CH2CH3), 24.88 (C-3), 18.52 (C-4), 14.18 (CH2CH3).…”

“…Evaporation of the solvent and subsequent distillation under reduced pressure gave a slightly yellow viscous oil. It was a mixture of the cis and trans isomers (1:9 by 13C NMR): yield 28.4 g (71%); bp 98-107 °C (0.4 mmHg); IR (neat) 3400 (t-o_H), 1740 (¡>c-o)> 1210 (i'c-o-c)i 1090 (pc-o-c) cm™1; 1H NMR (CDC13) cis isomer, 4.24 (q, J = 7.2 Hz, 2 H, Cíf2CH3), 4.05 (dd, J = 2.6 Hz, J = 10.6 Hz, 1 H, H-6), 3.97 (dd, J = 2.5 Hz, J = 11.7 Hz, 1 H, H-2), 3.82-3.68 (m, 1 , H-5), 3.65 (dd, J = 2.2 Hz, J = 10.6 Hz, 1 , H-6), 2.50 (br, 1 H, OH), 2.15-1.75 (m, 4 , 2H-3 and 2H-4), 1.29 (t, J = 7.2 Hz, 2H-3 CH2CH3); NMR trans isomer, 4.23 (q, J = 7.2 Hz, 2 H, CH2CH3), 4.12 (dd, J = 4.5 Hz, J = 11.0 Hz, 1 , H-6), 3.95 (dd, J = 2.4 Hz, J = 10.4 Hz, 1 , H-2), 3.85-3.70 (m, 1 , H-5), 3.21 (dd, J = 9.6 Hz, J = 11.0 Hz, 1 , H-6), 2.50 (br, 1 H, OH), 2.25-1.40 (m, 4 , 2H-3 and 2H-4), 1.29 (t, J = 7.2 Hz, 3 H, CH2CH3); 13C NMR (CDClg) cis isomer, 171.48 (C=0), 75.73 (C-2), 71.88 (C-6), 63.98 (C-5), 61.21 (CH2CH3), 29.43 (C-3), 23.62 (C-4), 14.18 (CH2CH3); 13C NMR trans isomer, 171.14 (0=0), 75.43 (C-2), 72.02 (C-6), 64.96 (C-5), 61.21 (CH2CH3), 31.67 (C-3), 27.24 (C-4), 14.18 (CH2CH3).…”

Synthesis of Degradable Polyesters Having Pendant Ester Groups by Ring-Opening Polymerization of 4-Substituted 2,6-Dioxabicyclo[2.2.2]octan-3-one Derivatives

“…10 potassium hydroxide. Transesterification took place during the saponification, and subsequent neutralization of the reaction products with hydrochloric acid gave the monoesters 12-14, respectively.…”

Synthesis of polyesters having pendant ester groups by ring-opening polymerization of 4-methoxycarbonyl-2,6-dioxabicyclo[2.2.2]octan-3-one

“…(5) Worsfold, D. J.; Bywater, S. Macromolecules 1978, 11, 582. (6) Glaze, W. H.; Hanicak, J. E.; Moore M. L.; Chaudhuri, J. J. Organometal. Chem.…”