Compounds of Formula I are provided where R
1
and R
2
are independently selected from H or hydroxy protecting groups. Such compounds may be used in preparing pharmaceutical compositions and are useful in treating a variety of biological conditions.
提供了符合式I的化合物,其中R1和R2分别选自H或羟基保护基团。这些化合物可用于制备药物组合物,并可用于治疗各种
生物条件。