Table 1. Ring-opening polymerization of 2,3-Dihydro-5H-1,4-benzodioxepin-5-one (2,3-DHB) using TBD as a catalyst under various conditions.^a .

Initiator	nTBD b / mmol	n2,3-DHB / mmol	c2,3-DHB / mg mL-1	Mcal. c / g mol-1	Conv.d / %	Mn e / g mol-1	PDIe
Benzyl alcohol	0.173	3.11	1,020	3,000	57	1,800	1.18
	0.011	3.11	1,020	45,000	50	21,000	1.19
	0.011	3.11	1,700	45,000	71	31,000	1.35
	0.057	12.2	2,857	35,000	79	28,000	1.13
Azido propanol	0.300	1.83	2,727	1,000	76f	750f	1.67
	0.250	3.05	2,941	2,000	54	1,100	1.31
	0.080	9.75	2,909	20,000	69	15,000	1.24
	0.100	12.2	3,333	20,000	87	19,000	1.33
	0.053	9.75	2,909	30,000	72	24,000	1.23

^aReactions were performed for three days at 40°C in chloroform.

^bThe same molar amount was used for the initiator.

^cMolecular mass calculated from the ratio of the reactants used.

^dConversion to polymer was determined by ¹H NMR spectroscopy.

^eThe number-average molecular weight M_n and polydispersity index PDI were determined by GPC in chloroform using PMMA standards.

^fConversion and molecular mass of this entry refer to an average of the polymeric and oligomeric species obtained for this reaction.