| —— | 
                                        (1R,2S,3S,5aR,10aR)-1',2',5a,6,7,8,10,10a-octahydro-3-(2-methyl-1-propenyl)-2',5,10-trioxospiro[1H,5H-dipyrrolo[1,2-a:1',2'-d]pyrazine-2(3H),3'-[3H]indole]-1-carboxylic acid ethyl ester | 
                                        282735-70-0 | 
                                        C24H27N3O5 | 
                                        437.495 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (1R,2S,3S,5aR,10aR)-1',2',5a,6,7,8,10,10a-octahydro-3-(2-methoxy-2-methylpropyl)-2',5,10-trioxospiro[1H,5H-dipyrrolo[1,2-a:1',2'-d]pyrazine-2(3H),3'-[3H]indole]-1-carboxylic acid ethyl ester | 
                                        282735-69-7 | 
                                        C25H31N3O6 | 
                                        469.538 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (3S,3'S,4'R,6'S,8'R,8'aR)-1,2,3',4',8',8a'-hexahydro-6'-(2-methoxy-2-methylpropyl)-1',2-dioxo-3',4'-diphenylspiro[3H-indole-3,7'(6'H)-[1H]pyrrolo[2,1-c][1,4]oxazine]-8'-carboxylic acid ethyl ester | 
                                        282735-67-5 | 
                                        C34H36N2O6 | 
                                        568.67 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (2'S,3S,4'R,5'R)-1,2-dihydro-2'-(2-methoxy-2-methylpropyl)-2-oxo-5'-[[(2R)-2-[(phenylmethoxy)carbonyl]-1-pyrrolidinyl]carbonyl]spiro[3H-indole-3,3'-pyrrolidine]-4'-carboxylic acid ethyl ester | 
                                        282735-71-1 | 
                                        C32H39N3O7 | 
                                        577.678 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (2'R,3S,3'R,5'S)-3'-ethoxycarbonyl-5'-(2-methoxy-2-methylpropyl)-2-oxospiro[1H-indole-3,4'-pyrrolidine]-2'-carboxylic acid | 
                                        473896-06-9 | 
                                        C20H26N2O6 | 
                                        390.436 |