Table 2.

¹³C NMR spectroscopic data of compounds 1–4

No	1*a	2*b	3*c	4*b
1	162.3	163.1	162.2	162.2
2	117.3	117.1	117.1	117.6
3	146.8	146.4	146.3	147.1
4	121.8	121.1	121.4	121.8
5	112.5	112.2	112.0	110.9
6	164.6	163.6	163.9	165.7
7	107.7	106.6	107.2	105.9
8	161.9	161.8	161.9	161.6
9	188.5	188.2	188.2	188.6
10	57.7	57.2	57.2	58.0
1a	117.5	116.8	117.4	118.1
4a	143.0	142.2	140.7	141.1
5a	146.4	145.9	146.1	146.5
8a	117.1	116.3	116.7	117.6
3-Me	21.8	21.8	21.7	21.9
1′	162.6	162.6	162.8	162.8
2′	117.7	117.3	117.3	117.4
3′	148.3	147.8	147.7	147.5
4′	122.2	122.1	122.0	122.2
5′	109.7	108.3	108.9	110.7
6′	166.4	166.4	166.8	167.8
7′	100.7	101.5	101.1	103.3
8′	165.7	165.4	165.3	165.7
9′	191.3	191.4	191.2	191.0
10′	56.7	56.4	56.3	56.7
1a′	116.0	115.2	114.7	115.3
4a′	140.0	140.7	139.7	140.3
5a′	143.1	144.4	145.4	145.8
8a′	111.5	111.4	112.2	111.1
3′-Me	22.1	22.0	22.2	22.3
1″	106.1	105.1	106.5	105.9
2″	74.9	74.5	74.9	74.9
3″	78.8	78.4	78.6	78.9
4″	71.2	71.3	71.3	71.5
5″	77.4	77.1	77.1	77.4
6″	62.7	62.8	62.9	62.7
6′-0Me	56.5	56.2	56.2	56.4

^{a 13}CNMR data were measured in CD₃OD at 125 MHz

^{b 13}CNMR data were measured in CD₃COCD₃ or CD₃OD at 150 MHz

^{c 13}CNMR data were measured in CD₃COCD₃ at 125 MHz