Enantioselective Synthesis of (−)-Basiliskamide A

Abstract

Basiliskamide A is an antifungal polyketide natural product isolated by Andersen and co-workers from a Bacillus laterosporus isolate, PNG-276. A nine-step enantioselective synthesis of basiliskamide A is reported, starting from commercially available β-hydroxy ester 7. The synthesis features a highly diastereoselective mismatched double asymmetric δ-stannylallylboration reaction of aldehyde 5 with the bifunctional allylborane reagent 4.

Are Alkyne Reductions Chemo-, Regio-, and Stereoselective Enough To Provide Pure (Z)-Olefins in Polyfunctionalized Bioactive Molecules?

“…Many biologically active molecules incorporate carbon−carbon double bond(s) with well-defined configurations (E or Z), such as β-carotene, 1 polyene antifungal drugs, 2,3 crocacine, 4 but also polyunsaturated fatty acids (PUFAs), pheromones, 5−7 and cruentaren. 8 In the last few decades, several methods have been developed to stereochemically control the desired configurations: (i) creation of carbon−carbon double bonds (e.g., Wittig, 9,10 Horner−Emmons−Wadsworth, 11 Julia−Kocienski, 12 Peterson, 13 Takai olefination, 14 olefin metathesis); 15,16 (ii) cross-coupling reactions; 17 (iii) reduction of alkynes; 18−20 and (iv) elimination of halides.…”

Efficient Z-Selective Olefin-Acrylamide Cross-Metathesis Enabled by Sterically Demanding Cyclometalated Ruthenium Catalysts

“…The streamlined access to ( Z )-α,β-unsaturated amides is highly desirable because of their versatile utility as synthetic intermediates and bioactive molecules, e.g., covalently acting protein modulators (Scheme b) . Only a few conventional methods are available to date, but all rely on the use of prefunctionalized, advanced intermediates . An alternative, stereoretentive cross-metathesis approach was recently achieved using ( Z )-but-2-enamides and in situ -formed ( Z )-2-alkenes, but access to these internal alkene starting materials, especially the ( Z )-but-2-enamides, is nontrivial. − We now report efficient Z -selective acrylamide-olefin metathesis by a novel, sterically demanding cyclometalated Ru catalyst that features high yield, high Z -selectivity, single operation (i.e., without adding the catalyst in portions), and use of readily available feedstocks (Scheme c).…”

Physiological properties and genomic insights into the plant growth‐promoting rhizobacterium Brevibacillus laterosporus K75 isolated from maize rhizosphere

“…In the present study, B. laterosporus K75 displayed antifungal activity against F. solani and F. oxysporum , and both bogorol and brevicidine, as well as basiliskamide A, were found by genome mining. According to Chen and Roush, 50 basiliskamide A is an antifungal polyketide natural product isolated from Bacillus laterosporus isolate. We can presume that the three polyketides and siderophores mentioned above are responsible for the antifungal activity of B. laterosporus K75.…”