Table 2.

¹H NMR spectroscopic data (δ) for compounds 1−4^a (δ in ppm, J in Hz).

No.	1	2	3	4
1	1.94, overlap	1.70, td (13.8, 3.5)	3.57, d (3.0)	1.66, overlap
	1.59, m	1.14, d (12.5)		1.26, br d (12.8)
2	2.31, m	1.98, overlap	2.10, overlap	1.98, overlap
	2.03, overlap	1.56, d (11.6)	1.64, overlap	1.57, m
3	4.34, br d (5.5)	4.22, br s	1.72, td (13.7, 4.0)	5.21, br s
			1.50, overlap
6		4.04, br s	2.03, td (13.8, 2.4)	3.92, br s
			1.62, overlap
7	3.14, t (12.9)	2.11, m	1.87, overlap	1.62, overlap
	2.09, dd (13.0, 4.9)	1.35, overlap	1.24, br d (12.1)
8	1.94, overlap	1.77, m	1.52, overlap	1.41, m
9	2.71, m	2.09, m	2.56, m	1.72, overlap
11	2.22, m	2.01, overlap	2.12, overlap	1.70, overlap
	2.02, overlap	1.95, overlap	1.84, overlap	1.00, qd (13.0, 3.6)
12	5.66, br s	5.63, t (3.5)	5.63, t (3.8)	2.35, d (12.9)
				1.98, overlap
14	2.47, m	2.32, m	2.38, m	2.25, t (9.8)
15	1.08, d (7.0)	0.87, d (6.8)	0.92, d (6.9)	5.62, ddd (17.2, 9.8, 9.8)
16	6.25, dd (17.7, 10.9)	6.20, dd (17.6, 10.9)	6.20, dd (17.6, 10.9)	5.13, dd (10.2, 2.0)
				4.98, dd (17.2, 2.0)
17	5.09,d (17.7)	5.08,d (17.6)	5.07,d (17.6)	4.64, d (1.1)
	4.92, d (10.9)	4.90, d (10.9)	4.89, d (10.9)	4.48, br s
18	1.50, s	1.36, s	1.12, s	1.32, s
20	0.89, s	0.96, s	0.70, s	0.91, s
1-OH			5.50, d (4.0)
3-OH		6.23, br s		6.23, d (2.5)
5-OH		6.10, br s	5.15, s	6.20, br s
6-OH				7.21, br s
19-OH			12.11, s	14.32, br s

^aNMR data (δ) were measured at 500 MHz in CD₃OD for 1 and at 600 MHz in DMSO-d₆ for 2−4.