“…155–157 A subclass of this family of natural products has drawn particular interest, because the tetronate or tetramate namesake appears to have undergone an intramolecular Diels-Alder reaction with a 1,3-diene to form a cyclohexene ring with a tertiary carbon joint. 12,157 Examples of such spirotetronates and spirotetramates are shown in Figure 6 and include versipelostatin ( 74 ), 158–161 pyrroindomycin ( 75 ), 162–166 chlorothricin ( 76 ), 167–175 kijanimicin ( 77 ), 176–181 the quartromicins ( 78 ), 182–186 the abyssomicins ( 79 ), 187–192 tetrocarcin, 193–198 the lobophorins, 199–205 nomimicin, 206 maklamicin, 207–209 and tetronothiodin. 210–214 Furthermore, several of these compounds also possess a second, decalin ring system, the formation of which is highly reminiscent of the reactions catalyzed by LovB and solanapyrone synthase (see above).…”