Formal Total Synthesis of Platencin

Abstract

Der richtige Bicyclus: Die effiziente sauerstoffvermittelte palladiumkatalysierte Cycloalkenylierung von 1 zu einem Bicyclo[3.2.1]octan und die desoxygenierende Umlagerung des Tosylhydrazons 2 zum Bicyclo[2.2.2]octan 3 sind wesentliche Schritte der Synthese der Kernstruktur 4 von Platencin, deren Gesamtausbeute nach 13 Stufen ausgehend von einer käuflich erhältlichen Verbindung 17.5 % betrug. Ts=p‐Toluolsulfonyl, TBS=tert‐Butyldimethylsilyl, Piv=Pivaloyl.magnified image

Recent Advances on Platensimycin: A Potential Antimicrobial Agent

“…O Ni-promoted 1,4-addition: ref [63] Isomerization: ref [64,70] Pinacol coupling: ref [66] Diels-Alder reaction: ref [67,68] Radical cyclization: ref [65,71] Rearrangement: ref [69] 93 Fig. (6).…”

“…The Dies-Alder reaction between methylcyclopentadiene (65) and methyl acrylate (66), followed by nitrosoaldol reaction and oxidative decarboxylation, produced ketone (68). Baeyer-Villiger oxidation of (68) gave lactone (69), which was converted into enone (70) for the Robinson annulation in moderate yield via four steps. Treatment of (57) with Lproline mediated the Michael addition, followed by dehydration, afforded ((-)-6) enantioselectively.…”

“…Due to platencin possessing a similar profile to platensimycin, therefore, the key intermediate tetracyclic enone (93) had been confirmed as an appealing strategy for the synthesis of platencin. To date, many groups have also embarked on the total syntheses of platencin [63][64][65][66][67][68][69][70][71] because of its unique mode of action and remarkable antibiotic activity. The strategic bond formed to complete enone (93) are summarized and presented in Fig.…”

The Construction of All‐Carbon Quaternary Stereocenters by Use of Pd‐Catalyzed Asymmetric Allylic Alkylation Reactions in Total Synthesis

“…Maier completed a formal synthesis of platencin ( 82 , Scheme 10) [31] by employing a decarboxylative allylic alkylation reaction to establish the substitution around a central quaternary carbon atom joining three different rings. Beginning from vinylogous ester 70 , formylation and allyl enol carbonate construction provided rapid access to allylic alkylation substrate 71 as a mixture of E and Z isomers.…”

Dialkylamino‐2,4‐dihydroxybenzoic Acids as Easily Synthesized Analogues of Platensimycin and Platencin with Comparable Antibacterial Properties

“…We chose compound 8 as the lead structure and designed a second set of structurally related compounds (Figure 4; compounds [16][17][18][19][20][21][22][23]. Compounds 16 and 17 tested the importance of the carboxylic acid moiety by either deleting it or modifying it to its methyl ester.…”