Table 1.

NMR data of compounds 1 and 2 in CDCl₃ (¹H: 500 MHz; ¹³C: 125 MHz; δ in ppm, J in Hz).

Position	1		2
	δ H	δ C	δ H	δ C
1	-	67.5	-	67.5
2	3.27 (1 H, dd, 6.8, 7.7)	59.4	3.15 (dd, 1 H, 1.6, 4.8)	61.8
3	2.16 (1 H, ddd, 3.1, 7.7, 14.2)	27.0	2.15 (ddd, 1 H, 3.1, 4.8, 15.6)	26.8
	1.53 (1 H, ddd, 6.8, 13.3, 14.2)		1.53 (ddd, 1 H, 1.6, 13.3, 15.6)
4	1.88 (1 H, m)	48.3	2.25 (ddd, 1 H, 3.1, 13.3, 13.5)	46.1
5	-	43.3	-	41.8
6	1.85 (1 H, dd, 12.6, 16.3)	50.1	1.87 (1 H,dd, 5.0, 16.3)	48.4
	1.66 (1 H, dd, 1.6, 16.3)		1.46 (1 H, dd, 11.6, 16.3)
7	3.85 (1 H,dd, 1.6, 12.6)	72.6	4.29 (1 H,dd, 5.0, 11.6)	68.2
8	1.61 (1 H, m)	42.9	1.47 (1 H, m)	43.3
	1.41 (1 H, m)		1.40 (1 H, m)
9	1.92 (1 H, m)	29.9	1.85 (1 H, m)	29.6
	1.77 (1 H, m)		1.76 (1 H, m)
10	2.95 (1 H, ddd, 2.2, 13.5, 13.6)	50.0	2.92 (1 H, ddd, 2.2, 13.4, 14.3)	50.7
11	-	149.0	-	148.3
12	4.79 (1 H, d, 1.3)	113.4	4.85 (1 H, d, 1.3)	113.9
	4.68 (1 H, d, 1.3)		4.74 (1 H, d, 1.3)
13	1.66 (3 H, s)	23.2	1.73 (3 H, s)	23.4
14	3.90 (1 H, d, 12.9)	60.6	4.07 (1 H, d, 12.5)	61.8
	3.75 (1 H, d, 12.9)		3.30 (1 H, d, 12.5)
15	0.99 (3 H, s)	18.3	0.85 (3 H, s)	18.3