ethyl 5-amino-3-methylsulfanyl-1H-pyrazole-4-carboxylate 、
methyl (3E)-4,6-O-benzylidene-3-[(dimethylamino)methylene]-3-deoxy-α-D-erythro-hexopyranosid-2-ulose 在
sodium hydride 作用下,
以
四氢呋喃 为溶剂,
以40%的产率得到ethyl (2R,4aR,6S,12bS)-4a,12b-dihydro-6-methoxy-9-methylsulfanyl-2-phenyl-4H,6H-[1,3]dioxino[4'5':5,6]pyrano[3,4-d]pyrazolo[1,5-a]pyrimidine-8-carboxylate