| —— | 
                                        (4R,10bR)-4,5,10,10b-Tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-2,4-dicarboxylic acid diethyl ester | 
                                        121994-31-8 | 
                                        C18H19N3O5 | 
                                        357.366 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-tert-Butyl-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-23-8 | 
                                        C19H23N3O3 | 
                                        341.41 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-(1-Methyl-1-phenyl-ethyl)-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-22-7 | 
                                        C24H25N3O3 | 
                                        403.481 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        2-(1-cyano-1-methylethyl)-5-(ethoxycarbonyl)-4,5,6,11b-tetrahydro-Δ4-1,2,4-oxadiazolino<3,2-a>-β-carboline | 
                                        106544-23-4 | 
                                        C19H20N4O3 | 
                                        352.393 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-Trichloromethyl-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-30-7 | 
                                        C16H14Cl3N3O3 | 
                                        402.664 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-(1-Cyano-2,2-bis-methylsulfanyl-vinyl)-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-29-4 | 
                                        C20H20N4O3S2 | 
                                        428.536 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        2,2-dimethyl-5-(ethoxycarbonyl)-4,5,6,11b-tetrahydroisoxazolidino<2,3-a>-β-carboline | 
                                        99708-07-3 | 
                                        C18H22N2O3 | 
                                        314.384 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-Dimethylamino-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-32-9 | 
                                        C17H20N4O3 | 
                                        328.371 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-(1-Ethoxycarbonyl-1-methyl-ethyl)-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-21-6 | 
                                        C21H25N3O5 | 
                                        399.447 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (exo)-1-carboxymethyl-5-ethoxycarbonyl-4,5,6,11b-tetrahydroisoxazolidino-<2,3-a>-β-carboline | 
                                        99708-08-4 | 
                                        C18H20N2O5 | 
                                        344.367 | 
                                    
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    
                                                        
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                
                                        | —— | 
                                        2-(1-cyano-2-phenylvinyl)-5-(ethoxycarbonyl)-4,5,6,11b-tetrahydro-Δ4-1,2,4-oxadiazolino<3,2-a>-β-carboline | 
                                        106544-22-3 | 
                                        C24H20N4O3 | 
                                        412.448 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-(1-Methyl-1-nitro-ethyl)-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-20-5 | 
                                        C18H20N4O5 | 
                                        372.381 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-[(E)-2-(4-Chloro-phenyl)-1-cyano-vinyl]-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-26-1 | 
                                        C24H19ClN4O3 | 
                                        446.893 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (5R,11bR)-ethyl 2-phenyl-5,6,11,11b-tetrahydro-[1,2,4]oxadiazolo[2',3':1,2]pyrido[3,4-b]indole-5-carboxylate | 
                                        121994-33-0 | 
                                        C21H19N3O3 | 
                                        361.4 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-p-Tolyl-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        122021-65-2 | 
                                        C22H21N3O3 | 
                                        375.427 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-(4-Formyl-phenyl)-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-41-0 | 
                                        C22H19N3O4 | 
                                        389.411 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-(1-Cyano-2,2-diphenyl-vinyl)-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-28-3 | 
                                        C30H24N4O3 | 
                                        488.546 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-(4-Nitro-phenyl)-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-40-9 | 
                                        C21H18N4O5 | 
                                        406.398 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-(4-Carboxy-phenyl)-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-42-1 | 
                                        C22H19N3O5 | 
                                        405.41 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-((E)-1-Cyano-2-furan-2-yl-vinyl)-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-27-2 | 
                                        C22H18N4O4 | 
                                        402.409 | 
                                    
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
                                                        
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        
                                        | —— | 
                                        2-(1-cyano-2-phenylcyclopropyl)-5-(ethoxycarbonyl)-4,5,6,11b-tetrahydro-Δ4-1,2,4-oxadiazolino[3,2-a]-β-carboline | 
                                        106544-19-8 | 
                                        C25H22N4O3 | 
                                        426.475 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        2-(1-cyanonorcaran-7-yl)-5-(ethoxycarbonyl)-4,5,6,11b-tetrahydro-Δ4-1,2,4-oxadiazolino<3,2-a>-β-carboline | 
                                        106544-21-2 | 
                                        C23H24N4O3 | 
                                        404.469 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-(4-Methoxy-phenyl)-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-44-3 | 
                                        C22H21N3O4 | 
                                        391.426 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (4R,10bR)-2-(4-Chloro-phenyl)-4,5,10,10b-tetrahydro-3-oxa-1,3a,10-triaza-cyclopenta[a]fluorene-4-carboxylic acid ethyl ester | 
                                        121994-43-2 | 
                                        C21H18ClN3O3 | 
                                        395.845 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (6R,7aR,11aR,11bS)-5,6,7a,8,9,10,11,11a,11b,12-Decahydro-7-oxa-6a,12-diaza-indeno[1,2-a]fluorene-6-carboxylic acid ethyl ester | 
                                        99708-13-1 | 
                                        C20H24N2O3 | 
                                        340.422 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (1S,2R,4R,10bS)-2-Methyl-1,2,4,5,10,10b-hexahydro-3-oxa-3a,10-diaza-cyclopenta[a]fluorene-1,4-dicarboxylic acid diethyl ester | 
                                        121994-39-6 | 
                                        C20H24N2O5 | 
                                        372.421 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (6R,7aR,11aR,11bS)-11-Oxo-5,6,7a,8,9,10,11,11a,11b,12-decahydro-7-oxa-6a,12-diaza-indeno[1,2-a]fluorene-6-carboxylic acid ethyl ester | 
                                        99708-14-2 | 
                                        C20H22N2O4 | 
                                        354.406 |