Scalable Total Synthesis of (−)‐Berkelic Acid by Using a Protecting‐Group‐Free Strategy

Abstract

Supply chain: the polycyclic core of (-)-berkelic acid (1) was constructed in just one step from very simple starting materials. The total synthesis of 1 involves a seven-step linear sequence. Protection/deprotection steps were avoided and all but the last step were performed on a gram scale. This synthesis could solve the supply problem associated with the exhaustion of the natural source.

Gold Catalysis for Heterocyclic Chemistry: A Representative Case Study on Pyrone Natural Products

“…Thes elected examples compiled in Figure 2a re representative. [18,[95][96][97][98][99][100][101][102][103][104][105][106][107][108][109][110][111][112] Thed iversity and complexity of the structural motifs manifest in this personal selection may well encourage further research into p-acid-catalyzed heterocycle synthesis and applications to biologically relevant and structurally ever more demanding targets.…”

Nitrogenated Azaphilone Derivatives through a Silver‐Catalysed Reaction of Imines from ortho‐Alkynylbenzaldehydes

“…Members of this family of natural products include structurally simple compounds such as phomoeuphorbin B or more complex molecules such as berkelic acid (Scheme a). In this context, we have recently been involved in the development of new reactions for the construction of molecules structurally related to azaphilones, and in 2012, we reported a new total synthesis of (−)‐berkelic acid . At this point, the remarkable work developed by J.…”

“…In this context,w ehave recently been involved in the developmento fn ew reactions for the construction of moleculess tructurally relatedt oa zaphilones, [3] and in 2012, we reportedanew total synthesis of (À)-berkelic acid. [4] At this point, the remarkable work developed by J. A. Porco and co-workerso nt he synthesis of azaphilones should be mentioned.…”

(−)-Berkelic Acid

“…For the coupling of these two fragments, we adopted the method described by Rychnovsky and Swenson for the alkylation of anions derived from cyanohydrins. 19 This work was highlighted in Synfacts in an article written by Ley and Frost. Final treatment of the crude of this reaction with tetrabutylammonium fluoride (TBAF) led to the diester 37 in 88% yield.…”