(+/-)-<<(diethylamino)methyl>phenyl>oxosulfonium tetrafluoroborate 、
tert-butyl (3E,5S,6R)-3-[3-[(3R,5R,6S)-4-[(2-methylpropan-2-yl)oxycarbonyl]-2-oxo-5,6-diphenylmorpholin-3-yl]propylidene]-2-oxo-5,6-diphenylmorpholine-4-carboxylate 在
sodium hydride 作用下,
生成 (1S,3S,5S,6R)-1-[2-((3R,5R,6S)-4-tert-Butoxycarbonyl-2-oxo-5,6-diphenyl-morpholin-3-yl)-ethyl]-8-oxo-5,6-diphenyl-7-oxa-4-aza-spiro[2.5]octane-4-carboxylic acid tert-butyl ester