Table 1.

NMR data for 1 and 2 in CDCl₃.

position	δC	δH, mult (J, Hz)	δC	δH, mult (J, Hz)	HMBC
1			2
1	192.0		197.3
2	63.8		63.6
3	59.2	3.83, s	59.1	3.79, s	2, 4, 4a, 1′
4	192.3		191.1
4a	132.1		132.4
5	127.0	7.92, ddd (7.1, 2.1, 0.8)	119.2	7.44, dd (7.5, 0.9)	1, 4, 6, 7, 8, 8a
6	134.5	7.72, ddd (7.5, 7.1, 2.1)	137.1	7.55, dd (8.4, 7.5)	4, 4a, 5, 7, 8, 8a
7	134.7	7.72, ddd (7.5, 7.1, 2.1)	124.7	7.18, dd (8.4, 0.9)	1, 4a, 5, 6, 8, 8a
8	127.7	8.00, ddd (7.1, 2.1, 0.8)	162.1
8a	132.6		114.7
1a′	26.4	3.02, dd (15.4, 8.1)	26.0	3.04, dd (15.3, 8.1)	1, 2, 3, 2′, 3′
1b′		2.66, dd (15.4, 6.9)		2.58, dd (15.3, 6.8)	1, 2, 3, 2′, 3′
2′	115.6	5.06, ddq (8.1, 6.9, 1.0)	115.2	5.01, ddq (8.1, 6.8, 1.0)	2, 3, 3′, 4′, 5′
3′	137.5		137.7
4′	18.3	1.66, brs	18.2	1.63, brs	2′, 3′, 4′
5′	26.1	1.70, brs	26.1	1.68, brs	2′, 3′, 5′
OH-8				11.39, brs