trans-5'-Benzyl 1-(tert-butyl) 3'-oxohexahydro-5'H-spiro[piperidine-4,1'-pyrrolo[3,4-c]pyrrole]-1,5'-dicarboxylate 1g

trans-5'-Benzyl 1-(tert-butyl) 3'-oxohexahydro-5'H-spiro[piperidine-4,1'-pyrrolo[3,4-c]pyrrole]-1,5'-dicarboxylate 1g