| abstract |
The present invention provides a compound represented by the formula (D) and a method for preparing the same. Here, X 2 is a halogen, Pg is selected from H and an amino protecting group, and the amino protecting group is, for example, Cbz, Boc, Fmoc, Alloc, Teoc, methoxycarbonyl, or ethoxycarbonyl. The present invention also provides synthetic intermediate compounds of compounds represented by the formula (D) and methods for preparing them. |