Biomimetic Synthesis of Elysiapyrones A and B

Abstract

[reaction: see text] The total synthesis of bicyclo[4.2.0]octane natural products elysiapyrones A and B is described.

Transition metals in organic synthesis: Highlights for the year 2005

“…Synthetic targets include, the heterocyclic core of GE 2270 [34], peridinin [35], pyrones isolated from placobranchus ocellatus [36], terpenepolyketide natural products [37], dihydroxerulic and xerulinic acid [38], bipinnatin J [39], elipticine [40], (+)-7-deoxytrans-dihydronarciclasine [41], gambierol [42], taiwaniaquinol [43], (−)-scabronine G [44], garsubellin A [45], piericidin A1 and B1 [46], lucilactaene [47], fostriecin [48], lupine alkaloids [49], ␤-C-glycosides [50], (+)-crocacin D [51], lobatamide analogs [52], epoxyquinoid compounds [53,54], (+)-SCH 351448 [55], 3-methyl-2,5-dihydro-1-benzoxepin carboxylic acids [56], (+)-ochromycinone and (+)-rubiginone B 2 [57], EI-1941-1 and EI-1941-2 [58], mycothiazole [59], 6 -epiperidinin [60], aureothin and N-acylaureothamine [61], cyercene A and placidenes [62], herbindole B [63], (+)-tubelactomicin A [64], saudin [65], peroxyacarnoates A and D [66], aureothin, N-acetylaureothamine, aureonitrile [67], elysiapyrones [68], altromycin B [69], (+)-phorboxazole A and analogues [70,71], (−)-SNF4435 C and (+)-SNF4435 D [72], A2E [73], paracentrone [74]<...>…”

“…(68)) [611]. (68) Palladium catalyzed enantioselective allylic alkylation of allyl-enol carbonates derived from ketones [612,613]. A palladium-catalyzed asymmetric alkylation of 3-aryloxindoles with allyl acetate was developed [614].…”

“…A ruthenium-catalyzed allylic peroxide to bisepoxide was used in a synthesis of elysiapyrones (Eq. (359)) [68]. A gold-catalyzed ring-expansion of cyclopropanols and cyclobutanols was reported (Eq.…”

Biomimetic Electrocyclization Reactions toward Polyketide‐Derived Natural Products

“…Darias proposed a biosynthetic hypothesis for these optically active metabolites, which involved an enzyme-mediated Black 8π-6π electrocyclization cascade (stage 3), followed by a [4+2] cycloaddition of singlet oxygen and subsequent rearrangement of the corresponding endoperoxide (stage 4) [67]. Trauner et al used their experience in biomimetic electrocyclizations to investigate Darias' hypothesis, and developed a total synthesis of elysiapyrones A (125) and B (126) in racemic form [68]. They again called upon the Stille reaction to access the key (2E,4Z,6Z,8E)-polyene 118, from fragments 117 and 24, which was not isolated and underwent the 8π-6π electrocyclization cascade to afford the diastereoisomers 121 and 122.…”

Mapping the Chemistry of Highly Unsaturated Pyrone Polyketides

“…To this end, each isomer was reacted with singlet oxygen and then isomerized with RuCl 2 (PPh 3 ) 2 to afford elysiapyrones A and B 24. Concurrent with the previously discussed studies, we continued to pursue the synthesis of our original bicyclo[4.2.0]octadienes, the SNF compounds.…”