Betaenone synthesis

Before the biosynthetic studies, total synthesis of betaenone C (50) was completed through a biomimetic route as shown in Fig. 12 [40]. The synthetic strategy involving the intramolecular Diels-Alder reac-... 

C, 02]acetate exhibited that " 0-isotope-induced shifts were observed at C-16 and C-18 but not at C-1, C-2 and C-8 [43]. When P. betae was treated with cytochrome P450 inhibitor, ancymidol (1 mM), a less oxidized precursor named probetaenone I (57) was obtained [43]. Tbe structure and stereochemistry were confirmed by extensive NMR analysis and chiral synthesis via the similar route to that of betaenone C (50) [44]. Feeding experiments of C-labeled probetaenone I (57) demonstrated that the intermediate (57) was converted to betaenone B (49) [45]. Isolation of probetaenone I (57)... 

Fig. 12. Total synthesis of betaenone C (50) according to plausible biosynthetic route...

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