Enantioselective Total Synthesis of (−)-Dehydrobatzelladine C

Abstract

The oxidation of two tethered Biginelli adducts was examined as a potential key step in total syntheses of highly oxidized batzelladine and crambescidin alkaloids. Although angular hydroxyl substitution could not be introduced, dehydrogenation was readily accomplished. This latter conversion is a key step in the first total synthesis of dehydrobatzelladine C. [structure: see text]

Syntheses of cyclic guanidine-containing natural products

“…385,388,389 They further reported the synthesis of dehydrobatzelladine C ( 302 ) in 2004. 387 They found through synthetic studies that the originally proposed length of the alkyl chains and the relative stereochemistry of 301f were both incorrect. The tethered Biginelli reaction was used again to construct both tricyclic cores of 301f .…”

Polycyclic Guanidine Alkaloids from Poecilosclerida Marine Sponges

“…Over 53 derivatives have been isolated and their original structures, based on chemical degradation studies and extensive NMR and MS studies, have been revised since the development of their total synthesis. The structural and stereochemical complexity of this class of natural products have inspired the development of a number of new synthetic methodologies [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ], which in turn has led to several total syntheses [ 31 , 33 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ] beyond the scope of this review. Finally, these unique and fascinating structures are coupled with a wide range of biological activities due to the typical shape of their tricyclic skeleton.…”

Amide-transforming activity of Streptomyces: possible application to the formation of hydroxy amides and aminoalcohols

“…Aminoalcohols and their derivatives are important building blocks of many pharmaceuticals and other biologically active molecules (Ichikawa et al 1988;Collins et al 2004;Okamoto et al 2007) (Fig. 1).…”