| —— | 
                                        (2R,5R)-1-aza-2-(tert-butyl)-5-methoxycarbonyl-6,8-dioxo-7-[(Z)-1-hydroxy-3-(E)-heptylallylidene]-3-oxabicyclo[3.3.0]octane | 
                                        1571713-46-6 | 
                                        C22H33NO6 | 
                                        407.507 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (2R,5R)-1-aza-2-(tert-butyl)-5-methoxycarbonyl-6,8-dioxo-7-[(Z)-1-hydroxy-3-(E)-ethylphenylallylidene]-3-oxabicyclo[3.3.0]octane | 
                                        1571713-42-2 | 
                                        C23H27NO6 | 
                                        413.47 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (2R,5R)-1-aza-2-(tert-butyl)-5-methoxycarbonyl-6,8-dioxo-7-[(Z)-1-hydroxy-3-(E)-(4’-methylphenyl)allylidene]-3-oxabicyclo[3.3.0]octane | 
                                        1571713-18-2 | 
                                        C22H25NO6 | 
                                        399.444 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (2R,5R)-1-aza-2-(tert-butyl)-5-methoxycarbonyl-6,8-7-[(Z)-1-hydroxy-1’-(E,E-phenyldienyl)vinylidene]dioxo-3-oxabicyclo[3.3.0]octane | 
                                        1571713-61-5 | 
                                        C23H25NO6 | 
                                        411.455 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (2R,5R)-1-aza-2-(tert-butyl)-5-methoxycarbonyl-6,8-7-[(E)-1-hydroxy-1’-(E,E-phenyldienyl)vinylidene]dioxo-3-oxabicyclo[3.3.0]octane | 
                                        1571713-63-7 | 
                                        C23H25NO6 | 
                                        411.455 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (2R,5R)-1-aza-2-(tert-butyl)-5-methoxycarbonyl-6,8-7-[(Z)-1-hydroxy-3-(E)-(2’-furan)allylidene]dioxo-3-oxabicyclo[3.3.0]octane | 
                                        1571713-65-9 | 
                                        C19H21NO7 | 
                                        375.378 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (2R,5R)-1-aza-2-(tert-butyl)-5-methoxycarbonyl-6,8-dioxo-7-[(Z)-1-hydroxy-3-(E)-(4’-chlorophenyl)allylidene]-3-oxabicyclo[3.3.0]octane | 
                                        1571713-27-3 | 
                                        C21H22ClNO6 | 
                                        419.862 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (2R,5R)-1-aza-2-(tert-butyl)-5-methoxycarbonyl-6,8-7-[(Z)-1-hydroxy-3-(E)-(2’-thiophene)allylidene]dioxo-3-oxabicyclo[3.3.0]octane | 
                                        1571713-67-1 | 
                                        C19H21NO6S | 
                                        391.445 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        (2R,5R)-1-aza-2-(tert-butyl)-5-methoxycarbonyl-6,8-dioxo-7-[(Z)-1-hydroxy-3-(E)-(4’-methoxyphenyl)allylidene]-3-oxabicyclo[3.3.0]octane | 
                                        1571713-24-0 | 
                                        C22H25NO7 | 
                                        415.443 |