ROP of rac-lactide initiated by 8–10^a.

Entry	Catalyst	Time (min)	M n,theo c (kg mol−1)	M n,obs d (kg mol−1)	P i e	Đ f	Conv.g (%)
1	8	60	13.54	12.39	0.65	1.11	94
2	9	60	10.52	15.33	0.54	1.13	73
3	10	60	13.11	19.52	0.49	1.22	91
4	8	100	14.27	15.36	0.60	1.13	99
5	9	100	13.84	34.60	0.59	1.28	96
6	10	100	13.98	21.97	0.50	1.40	97
7b	8	240	12.35	0.14	—	2.02	85
8b	9	180	3.86	0.32	—	2.04	26
9	1a–3	240	—	—	—	—	Traces

^aReaction conditions: [LA] : [catalyst] = 100 : 1, [LA] = 1 M in toluene.

^b[LA] : [catalyst] : [BnOH] = 100 : 1 : 1, 403 K. Unless otherwise stated.

^cThe theoretical molecular weight calculated from conversion {([LA] : [catalyst] × (% conv.) × 144.13)} or {([LA] : [catalyst] × (% conv./no. eq BnOH × 144.13)) + 108.14}.

^dDetermined by GPC analysis calibrated using narrow MW polystyrene standards, in THF and corrected by Mark–Houwink parameter (0.58).

^eDetermined by relative integration of PLA methine tetrads in the ¹H{¹H} NMR spectrum using values predicted according to Bernoullian statistics.⁶⁸

^f Đ = M_w/M_n.

^gDetermined by integration of the methine region of the ¹H NMR spectrum at δ 4.98–5.06 ppm (LA) and δ 5.08–5.22 (PLA).