(2'S,3S,5'S)-methyl 1,2-dihydro-2'-(2-methylpropyl)-2-oxo-1'-(trifluoroacetyl)spiro<3H-indole-3,3'-pyrrolidine>-5'-carboxylate

(2'S,3R)-1'-(benzyloxycarbonyl)-2'(2-methylpropyl)spiro<3H-indole-3,3'-pyrrolidin>-2(1H)-one=