Table 1.

NMR spectroscopic data for antartin (1) ¹ in methanol-d₄.

Position	δc, Type 2	δH, (J in Hz)	COSY	HMBC
1	54.2, qC
2	38.7, CH	2.07, m	3a, 12	1, 3, 10, 11, 12
3a	41.7, CH2	1.49, m	2, 4	2, 12
3b		1.83, m		4, 5
4	53.9, CH	4.24, d (6.1)	3a	1, 2, 5, 6, 1′
5	146.8, qC
6	136.4, qC
7	42.4, qC
8	49.1, CH	1.90, m	9a, 9b, 10, 11	1, 6
9a	25.8, CH2	1.67, m	8, 10a	1, 8, 11
9b		1.84, m	8, 10b
10a	30.8, CH2	1.28, br	9a
10b		1.48, m	9b	1, 5, 8
11	38.6, CH2	1.60, d (3.0)	8	1, 5, 7, 8, 9, 10
12	14.3, CH3	0.94, d (6.8)	2	1, 2, 3
13	14.0, CH3	1.52, s		5, 6, 7
14	25.7, CH3	1.04, s		6, 7, 8, 15
15	29.6, CH3	1.10, s		6, 7, 8, 14
1′	152.1, qC
2′	111.9, qC
3′	133.7, CH	7.85, dd (6.9, 2.0)	4′	1′, 5′, 6′, 7′
4′	115.3, CH	6.51, dd (6.9, 6.9)	3′, 5′	2′, 3′, 5′, 6′
5′	135.5, CH	7.31, dd (6.9, 6.9)	4′, 6′	1′, 3′, 6′
6′	113.0, CH	6.69, dd (6.9, 2.0)	5′	2′, 4′, 7′
7′	172.5, qC

¹ 500 MHz for ¹H NMR and 125 MHz for ¹³C NMR. ² Multiplicity was determined by the analysis of 2D NMR spectroscopic data.