Table 1.

¹H NMR Spectroscopic Data (500 MHz, CDCl₃) for Compounds 1–6

	1a	2a	3a	4a	5b	6a
3	4.27, dd (4.0, 2.0)	4.55, dd (5.0, 2.0)	4.03, d (10.0)	4.02, d (10.0)	4.93, dd (8.5, 5.5)	4.41, dd (12.5, 5.0)
4	2.13, m	2.33, m	1.85, m	1.85, m	2.33, m	2.30, m
	1.93, m	1.88, m	1.72, m	1.71, m		2.13, m
5	2.82, ddd (19.0, 12.0, 7.0)	3.40, m	2.60, m	2.60, m	2.51, m	2.71, m
		2.41, m
	2.40, dd (19.0, 7.0)
7	-	-	3.13, s	3.13, d (7.5)	3.49, d (17.5)	-
					2.95, d (17.5)
11	-	-	-	-	-	6.12, s
13	6.07, s	6.11, s	6.12, s	6.10, s	6.35, s	-
16	3.69, s	3.68, s	3.74, s	3.73, s	3.64, s	3.74, s
3′	7.53, br s	7.54, br s	7.59, br s	7.54, d (1.5)	7.38 d (2.0)	7.53, br s
5′	7.10, br s	7.11, br s	7.10, br s	7.10, br s	7.15 d (2.0)	7.08, br s
11′	4.93, d (7.5)	4.96, d (7.5)	4.79, d (7.5)	4.92, d (7.5)	4.59 d (7.0)	5.21, d (7.5)
12′	6.42, dd (8.5, 7.5)	6.45, dd (8.5, 7.5)	6.50, dd (8.5, 7.5)	6.43, dd (8.5, 7.5)	6.45, dd (8.5, 7.5)	6.23, dd (8.5, 7.5)
13′	7.01, d (8.5)	7.02, d (8.5)	6.69, d (8.5)	7.02, dd (8.5, 1.0)	6.81, d (8.5)	7.05, d (8.5)
15′	3.18, s	3.20, s	3.07, d (18.0)	3.19, s	3.12, s	3.20, m
			2.91, d (18.0)
16′	2.48, s	2.49, s	2.47, s	2.48, s	2.49, s	2.46, s
6-OH	13.88, s	-	-	-	-	13.94, s
10-OH	12.13, s	12.18, s	12.15, s	12.29, s	12.15, s	11.17 s
6′-OH	10.68, s	10.69, s	11.71, s	10.66, s	10.51, s	10.62, s
9′-OH	nd	nd	nd	nd	8.00, s	nd

^aCDCl₃.

^bDMSO-d₆.