Table 1.

¹³C and ¹H NMR assignments for compounds 1–4^a.

No.	1 b		2 b		3 b		4 b
	ppm, Type	δ, mult (J in Hz)	ppm, Type	δ, mult (J in Hz)	ppm, Type	δ, mult (J in Hz)	ppm, Type	δ, mult (J in Hz)
1		10.10, s		10.20, s		10.20, s		10.10, s
2	106.9, C		106.9, C		107.0, C		107.0, C
4	160.1, C		161.1, C		161.1, C		160.9, C
5	166.4, C		166.4, C		166.1, C		166.2, C
1′		12.00, s		ND c		12.10, s		11.90, s
2′	132.9, CH	8.67, s	133.0, CH	8.68, s	133.9, CH	8.69, d (3.0)	132.9, CH	8.67, s
3′	105.9, C		105.9, C		106.0, C		106.0, C
3a′	125.6, C		125.6, C		124.6, C		124.4, C
4′	121.5, CH	8.18, d (7.8)	121.5, CH	8.18, d (7.8)	123.1, CH	8.17, d (7.8)	123.1, CH	8.09, d (8.2)
5′	121.5, CH	7.16, dd (8.0, 7.8)	121.6, CH	7.16, dd (7.8, 7.0)	124.4, CH	7.30, dd (7.8, 1.5)	124.6, CH	7.30, dd (8.2, 1.9)
6′	123.1, CH	7.23, dd (8.0, 7.4)	123.1, CH	7.23, dd (8.0, 7.0)	115.7, C		115.1, C
7′	112.2, CH	7.51, d (8.0)	112.4, CH	7.51, d (8.0)	115.1, CH	7.72, d (1.5)	115.7, CH	7.72, d (1.9)
7a′	136.4, C		136.5, C		137.4, C		137.4, C
1′′		11.80, s		ND c		12.20, s		ND c
2′′	136.4, CH	8.55, s	137.7, CH	8.74, s	137.7, CH	8.73, d (3.0)	123.1, CH	8.53, s
3′′	112.3, C		112.1, C		112.1, C		112.1, C
3a′′	119.5, C		126.7, C		126.7, C		119.5, C
4′′	121.7, CH	7.92, d (8.6)	121.2, CH	8.14, d (7.8)	121.2, CH	8.09, d (8.2)	121.7, CH	7.91, d (8.4)
5′′	112.2, CH	6.70, dd (8.6, 2.0)	122.2, CH	7.19, dd (7.8, 7.6)	122.3, CH	7.22, dd (8.2, 7.7)	112.7, CH	6.69, dd (8.4, 2.1)
6′′	154.2, C		123.0, CH	7.24, dd (8.0, 7.6)	123.0, CH	7.22, dd (7.7, 7.6)	154.3, C
7′′	97.5, CH	6.87, d (2.0)	112.4, CH	7.55, d (8.0)	112.4, CH	7.54, d (7.6)	97.5, CH	6.88, d (2.1)
7a′′	137.1, C		136.0, C		135.9, C		137.1, C
8′′	186.2, C		186.5, C		186.3, C		185.9, C
2-OMe	49.3, CH3	3.28, s	49.3, CH3	3.30, s	49.3, CH3	3.30, s	49.4, CH3	3.28, s

^a Data were obtained in DMSO-d₆. ^b Data were measured at 500/125 (1 and 2) and 800/200 (3 and 4) MHz for ¹H/¹³C, respectively. ^c Not detected.