propyl 5-((benzyloxy)methyl)-4-(but-1-en-2-yl)-6-methoxypicolinate

5-Benzyloxymethyl-4-((S)-1-formyl-1-hydroxy-propyl)-6-methoxy-pyridine-2-carboxylic acid propyl ester

propyl 5-((benzyloxy)methyl)-4-(2-ethyl-1,3-dioxolan-2-yl)-6-methoxypicolinate

7-乙基-10-羟基喜树碱中间体

1-溴-2-戊炔