A compound represented by formula I, or its stereoisomers, salts, or pharmaceutically acceptable salts, hydrates, solvates, or crystalline forms thereof: ** Formula ** wherein ** Formula ** R1 is hydrogen or phenyl； R2 is hydrogen； R3a is hydrogen； R3b is CH3； R4 is hydrogen or cyclopentyl； R5 is hydrogen； R6 is CH3； X is F； R8 is OMe or OBn； and R9 is NH2.Un compuesto representado por la formula I, o sus estereoisomeros, sales, o sales farmaceuticamente aceptables, hidratos, solvatos o formas cristalinas de los mismos:**Fórmula** en la que**Fórmula** R1 es hidrogeno o fenilo； R2 es hidrogeno； R3a es hidrogeno； R3b es CH3； R4 es hidrogeno o ciclopentilo； R5 es hidrogeno； R6 es CH3； X es F； R8 es OMe u OBn； y R9 es NH2.
