¹H (600 MHz) and ¹³C NMR (150 MHz) NMR data for compounds 1–3.

Position	1a		2b		3b
	δ H (J in Hz)	δ C	δ H (J in Hz)	δ C	δ H (J in Hz)	δ C
1						132.3
2	8.09, s	156.0	8.19, s	157.2	6.98, br s	112.2
3		122.9		122.0		145.6
4		182.5		182.8		149.4
4a		104.8		106.0
5		157.2		158.1		130.4
6		106.5		107.0	6.98, br s	116.6
7		159.7		160.1	5.59, d (16.2)	134.3
8		103.2		103.8	6.19, m	124.3
8a		153.3		154.7
9	2.74, dd (17.4, 10.2)	21.8	2.73, dd (16.8, 10.8)	22.6	4.08, dd (6.0, 1.2)	74.3
	2.98, dd (17.4, 5.4)		2.99, dd (16.8, 4.8)
8-CH3	2.22, s	7.7	2.23, s	7.6
3-OCH3					3.90, s	56.8
9-OCH3					3.39, s	58.0
1′		120.4		119.8		134.3
2′		156.2		156.8	6.96, d (1.8)	110.6
3′	7.10, dd (7.8, 1.2)	119.8	6.94, dd (7.8, 1.2)	117.2		149.1
4′	7.36, ddd (7.8, 7.8, 1.8)	130.8	7.29, ddd (7.8, 7.8, 1.8)	132.7		147.7
5′	7.00, ddd (7.8, 7.8, 1.2)	121.3	6.92, ddd (7.8, 7.8, 1.2)	120.7	6.79, d (7.8)	116.2
6′	7.19, dd (7.8, 1.8)	129.9	7.26, dd (7.8, 1.8)	130.9	6.84, dd (7.8, 1.8)	119.9
7′					5.50, d (6.6)	89.7
8′					3.63, m	52.7
9′					3.65, m	75.7
					3.72, m
3′-OCH3					3.84, s	56.4
9′-OCH3					3.41, s	59.3
1′′		131.1		131.4
2′′	6.92, d (1.8)	109.1	6.73, s	105.3
3′′		147.0		149.4
4′′		146.1		136.7
5′′	6.95, d (7.8)	114.6		149.4
6′′	6.91, dd (7.8, 1.8)	120.0	6.73, s	105.3
7′′	5.02, d (9.0)	81.0	5.02, d (8.4)	82.0
8′′	2.25, m	39.7	2.26, m	40.8
9′′	3.55, dd (10.8, 4.8)	63.4	3.43, dd (10.8, 4.8)	63.4
	3.65, dd (10.8, 4.8)		3.55, dd (10.8, 4.8)
3′′-OCH3	3.92, s	56.2	3.87, s	56.8
5′′-OCH3			3.87, s	56.8
5-OH	12.54, s

^aRecorded in CDCl₃.

^bRecorded in methanol-d₄.