Figure 6.

Structures of compounds 99–105.

Cpd	R1	R2	R3	R4
99	β-OH	β-OH	H	α-OH
100	=O	=O	H	=O
101	=O	=O	β-O-Ac	=O
102	β-OH	=O	β-O-Ac	=O
103	β-OH	β-OH	β-OH	=O
104	=O	β-OH	OH	=O
105	β-OH	=O	OH	=O