NMR data of compound 5^a.

Position	δ C,b type	δ H (J in Hz)
2	170.9, C
3	109.6, CH	6.36, s
4	184.4, C
4a	113.1, C
5	n.d.c
5a	n.d.
6	168.6, CH
8	81.8, CH	6.04, br s
9	70.9, CH	4.92, br s
9a	125.6, C
10	103.6, CH	7.38, s
10a	158.1, C
11	170.6, C
12	20.3, CH3	2.51, s
OMe-11	52.4, CH3	3.73, s

^aMeasured in acetone-d₆ (¹H at 750 MHz and ¹³C at 175 MHz).

^bData were extracted from the HSQC and HMBC spectra.

^cn.d. = not detected.