Table 2.

¹H NMR Data of Compounds 4–6 in Methanol-d₄ (δ in ppm, J in Hz).

Position	4		5		6
	δH	δC	δH	δC	δH	δC
2		169.7		169.6		172.4
3	6.04, s	111.3	6.05, s	111.3	6.05, s	108.4
4		180.1		180.1		184.0
4a		109.1		109.2		105.2
5		162.1		162.1		163.2
6	6.49, d (2.1)	97.3	6.50, d (2.1)	97.2	6.17, d (2.0)	100.0
7		166.3		166.3		165.9
8	6.62, d (2.1)	94.0	6.64, d (2.1)	94.0	6.31, d (2.0)	94.9
8a		161.8		161.8		159.9
9	2.63, t (7.5)	34.4	2.63, t (7.7)	34.3	2.64, t (7.6)	34.9
10	1.76, m	27.8	1.76, m	27.7	1.75, m	27.8
11	1.52, m	26.1	1.52, m	26.0	1.52, m	26.0
12	1.52, m	37.6	1.54, m	37.6	1.53, m	37.6
13	3.99, m	69.3	4.0, m	69.1	3.99, m	69.1
14	2.41, m	43.6	2.41, dd (15.1, 8.1) 2.50, dd (15.1, 4.9)	43.2	2.39, dd (15.3, 7.9) 2.46, dd (15.3, 5.1)	43.3
15		174.5		174.0		175.7
5-OCH3	3.89, s	56.5	3.89, s	56.5
7-OCH3	3.90, s	52.0	3.91, s	56.5
15-OCH3			3.67, s	52.0