Table 1.

1H NMR data for compounds 6–8, 12, and 13^a,b

Proton	δH multiplet (J)
	6	7	8	12	13
H-2	4.08 d (2.7)	4.42 d (2.3)	4.73 d (2.25)	4.44 d (2)	5.14 d (2.5)
H-3	4.40 d (2.7)	4.02 d (2.3)	4.70 d (2.25)	5.11 d (2)	4.40 d (2.5)
H-18	0.68 s	0.68 s	0.69 s	0.69 s	0.68 s
H-19	0.99 s	0.99 s	0.99 s	1.01 s	0.93 s
H-21	0.93 d (6.6)	0.93 d (6.6)	0.93 d (6.6)	0.93 d (6.6)	0.93 d (6.6)
H-26	0.88 d (6.6)	0.88 d (6.6)	0.88 d (6.6)	0.88 d (6.6)	0.88 d (6.6)
H-27	0.88 d (6.6)	0.88 d (6.6)	0.88 d (6.6)	0.88 d (6.6)	0.88 d (6.6)
CH3CO				2.05 s	2.03 s

^aRecorded at 500MHz in methanol-d₄.

^bJ in Hz.