| —— | 
                                        methyl (1R,2S,6R,7R,12R,16R)-6-hydroxy-3-oxospiro[11,13,15-trioxatetracyclo[8.6.0.02,7.012,16]hexadec-9-ene-14,1'-cyclohexane]-7-carboxylate | 
                                        131691-23-1 | 
                                        C20H26O7 | 
                                        378.422 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        methyl (1R,2S,7R,12R,16R)-3,6-dioxospiro[11,13,15-trioxatetracyclo[8.6.0.02,7.012,16]hexadec-9-ene-14,1'-cyclohexane]-7-carboxylate | 
                                        131691-22-0 | 
                                        C20H24O7 | 
                                        376.406 | 
                                    
                                                                                                                                            
                                        | —— | 
                                        methyl (1R,2S,7R,12R,16R)-3,6-dioxospiro[11,13,15-trioxatetracyclo[8.6.0.02,7.012,16]hexadeca-4,9-diene-14,1'-cyclohexane]-7-carboxylate | 
                                        114439-93-9 | 
                                        C20H22O7 | 
                                        374.39 |