Table 3.

Comparison of partial NMR data of 1 and 2 with known compounds ^a.

Position	Szemaoenoid A		Szemaoenoid C		E		Compound 1		Compound 2
	δC	δH	δC	δH	δC	δH	δC	δH	δC	δH
15	40.9	2.71, 3.20	33.6	2.87, 3.17	40.4	2.70, 2.82	41.1	2.67, 3.25	41.1	2.67, 3.27
16	68.3	4.10	68.3	4.15	68.7	4.04	68.1	4.17	68.1	4.16
17	22.8	1.12	22.9	1.12	23.3	1.15	22.7	1.10	22.6	1.00

^a Spectra of all compounds were measured in CD₃OD. E = (5R,10S,16R)-11,16-dihydroxy-12 methoxy-17(15→16)-abeoabieta-8,11,13-trien-3,7-dione.