The ¹H NMR spectral data (δ in ppm, J in Hz) for compounds 1, 2 and 3.

Position	1a	2a	3b
2	7.34 (1H, d, 1.2)	6.92 (1H, d, 1.2)	5.21 (1H, d, 2.0)
3	—	—	3.15 (1H, brq, 7.2)
4	—	—	7.12 (1H, d, 7.6)
5	7.18 (1H, d, 8.4)	7.07 (1H, d, 7.6)	6.87 (1H, brd, 7.6)
6	7.35 (1H, dd, 8.4, 1.2)	6.84 (1H, dd, 7.6, 1.2)	—
7	9.92 (1H, s)	5.06 (2H, s)	6.79 (1H, brs)
9	4.47 (1H, d, 12.0)	4.73 (2H, s)	—
	4.33 (1H, d, 12.0)
10	1.66 (3H, s)	5.47 (1H, d, 1.2)	1.23 (3H, d, 7.2)
		5.28 (1H, d, 1.2)
11	—	—	4.53 (2H, s)
12	—	—	3.47 (3H, s)
2′	—	2.62 (1H, sept, 7.2)	—
3′	—	1.20 (3H, d, 7.2)	—
4′	—	1.20 (3H, d, 7.2)	—
2′′	2.57 (1H, sept, 7.2)	2.62 (1H, sept, 7.2)	—
3′′	1.12 (3H, d, 7.2)	1.20 (3H, d, 7.2)	—
4′′	1.13 (3H, d, 7.2)	1.20 (3H, d, 7.2)	—

^aRecorded at 600 MHz in CDCl₃.

^bRecorded at 400 MHz in CD₃OD.