{9-[(2R,3R,4R,5R)-4-Hydroxy-5-hydroxymethyl-3-(2-nitro-benzyloxy)-tetrahydro-furan-2-yl]-6-oxo-6,9-dihydro-1H-purin-2-yl}-carbamic acid (1R,4R)-1,7,7-trimethyl-bicyclo[2.2.1]hept-2-yl ester 、
Phosphoric acid (2R,3R,4R,5R)-5-(4-benzoylamino-2-oxo-2H-pyrimidin-1-yl)-2-[(4-methoxy-phenyl)-diphenyl-methoxymethyl]-4-(2-nitro-benzyloxy)-tetrahydro-furan-3-yl ester 4-chloro-phenyl ester 在
2,4,6-triisopropylbenzenesulfonyl 3-nitroimidazolidine 作用下,
以
吡啶 为溶剂,
以41%的产率得到