Table 1. NMR spectroscopic data for Isororidin A [400 (¹H) and 100 MHz (¹³C), δ ppm]^a.

Position (Scheme 1)	1H NMR (J in Hz)	13C NMR	COSY	HMBC	NOESY
2	3.74 (d, 5.1)	80.4	3b	4, 5, 12	3′, 13a
3	b: 2.14 (overlap by H-3′)	35.7	2, 4	2, 4
	a: 2.47 (dd, 8.2, 15.2)			2, 5, 12
4	5.84 (dd, 4.5, 8.2)	76.0	3	2, 3, 5, 6, 12, 11′	11
5	Cq	50.5
6	Cq	45.0
7	1.87 (m, 2H)	21.3	8	6, 8, 9, 11	13, 14
8	a: 1.93 (d, 8.0)	28.7	7	6,7, 9, 10
	b: 1.98 (m)
9	Cq	141.7
10	5.41 (d, 5.4)	119.7	11, 16	6, 8, 11, 16
11	3.72 (br d, 5.4)	68.5	10	7, 10, 15	4
12	Cq	66.4
13	2.86 (d, 4.0)	48.5		2, 5, 12	14
	3.05 (d, 4.0)
14	0.81 (s)	8.0	,	4, 5, 6, 12	2′, 3′, 15, 12′
15	4.32 (d, 12.2)	64.8	15	5, 6, 7, 1′	14
	4.46 (d, 12.2)			5, 6, 7, 11, 1′
16	1.72 (s)	23.3	10	8, 9, 10
1′	CO	175.6
2′	4.04 (d, 4.0)	76.7	3′	1′, 4′, 12′	14, 3′, 12′
3′	2.08 (m	37.7	2′, 12′	1′, 2′	14, 2′
4′	1.58 (m)	34.9	4′, 5′	3′, 5′, 12′
	1.73 (m)			2′, 3′, 5′
5′	3.50 (ddd, 5.2, 8.7, 9.1)	70.9	4′, 5′	3′, 4′, 6′
	3.58 (ddd, 5.2, 9.6, 9.8)
6′	3.82 (m)	84.6	7′, 13′	5′, 7′, 8′, 14′	8′, 14′
7′	6.17 (dd, 3.0, 15.4)	142.3	6′, 8′	6′, 8′, 9′	13′, 14′
8′	7.60 (ddt, 11.4, 15.4, 1.1)	126.8	7′, 9′	6′, 9′, 10′	14, 3′, 10′, 12′
9′	6.75 (t, 11.4)	145.5	8′, 10′	7′, 8′, 11′	7′
10′	5.76 (d, 11.2)	117.9	9′	8′, 9′, 11′	14
11′	CO	168.1
12′	1.09 (d, 6.8)	15.1	3′	2′, 3′, 4′	14, 2′, 3′, 8′
13′	3.69 (m)	71.0	6′, 14′	6′, 14′	7′, 8′, 14′
14′	1.16 (d, 6.4)	18.4	13′	6′, 13′	6′, 7′, 8′,13′

Note: (a) the assignments were based on ¹H–¹H COSY, HSQC–DEPT and HMBC experiments, and recorded in MeOD-d₄.