Table 1.

¹³C nuclear magnetic resonance (NMR) data of compounds 1 to 4.

Position	1 a	2 b	3 b	4 c
1	146.6, C	144.4, C	149.6, C	78.6, C
2	122.3, CH d	121.8, CH	124.8, CH	131.5, CH
3	51.0, CH	51.1, CH	58.1, CH	136.5, CH
4	82.8, C	82.8, C	62.1, C	72.3, C
5	40.3, CH2	37.7, CH2	37.8, CH2	43.9, CH2
6	25.5, CH2	23.0, CH2	23.5, CH2	22.3, CH2
7	50.5, CH	54.3, CH	126.4, CH	128.4, CH
8	74.5, C	75.2, C	133.7, C	132.8, C
9	37.9, CH2	44.1, CH2	35.9, CH2	39.0, CH2
10	25.4, CH2	23.1, CH2	24.0, CH2	23.9, CH2
11	90.7, CH	127.1, CH	59.1, CH	126.5, CH
12	148.1, C	132.3, C	60.4, C	136.3, C
13	30.3, CH2	36.0, CH2	73.2, CH	36.2, CH2
14	28.6, CH2	28.3, CH2	67.8, CH	32.7, CH2
15	32.7, CH	32.9, CH	28.9, CH	38.7, CH
16	21.1, CH3	21.2, CH3	24.2, CH3	16.7, CH3
17	23.7, CH3	23.8, CH3	24.0, CH3	17.6, CH3
18	25.8, CH3	25.2, CH3	17.5, CH3	27.8, CH3
19	27.1, CH3	22.1, CH3	15.9, CH3	14.8, CH3
20	117.4, CH2	17.3, CH3	16.2, CH3	14.7, CH3
13-OAc			20.7, CH3
			170.4, C
14-OAc			20.7, CH3
			169.0, C

^a Spectrum recorded in C₆D₆ at 125 MHz at 25 °C, ^b Spectra recorded in CDCl₃ at 100 MHz at 25 °C, ^c Spectrum recorded in CDCl₃ at 125 MHz at 25 °C, ^d Attached protons were determined by distortionless enhancement by polarization transfer (DEPT) experiments.