A compound of formula (I): which is substantially free of any of the corresponding compound of formula (IB): methods of making such compounds, and the further transformation of such compounds.
具有
化学式(I)的化合物:基本上不含有任何具有
化学式(IB)的相应化合物;制备这类化合物的方法,以及这类化合物的进一步转化。