(4R,5R,6R)-5-acetylamino-6-[(2-biphenyl-4-yl-ethyl)propylcarbamoyl]-4-(tert-butyldiphenylsilanyloxy)-5,6-dihydro-4H-pyran-2-carboxylic acid methyl ester 、
二碳酸二叔丁酯 在
4-二甲氨基吡啶 作用下,
以
1,4-二氧六环 为溶剂,
生成 (4R,5S,6R)-5-(Acetyl-tert-butoxycarbonylamino)-6-[(2-biphenyl-4-yl-ethyl)propylcarbamoyl]-4-(tert-butyldiphenylsilanyloxy)-5,6-dihydro-4H-pyran-2-carboxylic acid, methyl ester