Table 2.

¹H NMR Spectroscopic Data of Compounds 1–3 [δ_H, ppm, (J Hz)]^a

Proton	1	2	3
H-1	4.07, d (10.0)	3.85, d (9.1)	3.81, m
H-3	3.03, mb	2.82, mb	2.86, m
H-3	3.31, td (11.7, 4.2)	3.41, m	3.41, m
H-4	2.63, mb	2.41, m	2.44, m
H-4	2.80, mb	2.87, m	2.88, m
H-5	6.31, s	6.30, s	6.31, s
H-α	2.67, mb	2.62, m	2.62, m
H-α	3.09, mb	3.02, m	3.03, m
H-10	6.20 d, (2.0)	6.33, mb	6.35, mb
H-13	6.83, d (8.1)	6.81, mb	6.81, mb
H-14	6.72 dd, (8.1, 2.0)	6.80, mb	6.81, mb
H-1′	3.90, mb	3.88, mb	3.87, mb
H-3′	2.33, mb	2.33, td (11.4, 1.8)	2.33, mb
H-3′	2.86, m	2.85, m	2.86, m
H-4′	2.11, ddd (14.6, 11.3, 4.1)	2.12, ddd (15.9, 11.4, 4.5)	2.11, ddd (15.9, 12.5, 3.9)
H-4′	2.41, mb	2.41, mb	2.36, mb
H-8′	6.48, s	6.49, s	6.46, s
H-α′	2.70, mb	2.68, dd (13.1, 4.1)	2.69, dd (13.0, 4.0)
H-α′	3.24, dd (13.1, 2.1)	3.21, db (13.1)	3.20, db (12.6)
H-10′	6.39, dd (8.3, 2.2)	6.35, dd (8.3, 2.2)	6.33, db (2.1)
H-11′	6.59, dd (8.3, 2.6)	6.56, dd (8.3, 2.6)	6.54, dd (8.3, 2.5)
H-13′	6.97, dd (8.3, 2.6)	6.98, dd (8.3, 2.6)	6.98, dd (8.3, 2.5)
H-14′	7.57, dd (8.3, 2.2)	7.53, dd (8.3, 2.2)	7.52, dd (8.3, 2.1)
N-Me	-	2.25, s	2.25, s
6-OMe	3.78, s	3.78, s	3.76, s
7-OH	5.30, br	5.44, s	-
7-OMe	-	-	3.26, s
12-OMe	3.92, s	3.90, s	3.90, s
N′-Me	2.61, s	2.60, s	2.62, s
6′-OMe	3.52, s	3.53, s	3.49, s
7′-OMe	3.88, s	3.88, s	3.87, s

^aRecorded in CDCl₃ at 400 MHz and 300 K

^bSignal partially obscured