A short and scalable route to orthogonally O-protected 2-deoxystreptamine.

A seven-step synthesis of orthogonally O-protected 2-deoxy-streptamine has been developed from readily available neomycin, with an overall yield of 28%. Key chemical transformations include a chemoselective glycosidic bond hydrolysis and two regioselective protective group manipulations involving acetylation and deacetylation. The synthetic route is amenable to scale-up for the production of multigram quantities of enantiopure and orthogonally O-protected 2-deoxystreptamine, a versatile scaffold for the generation of libraries of RNA-targeting ligands.

Catalyst recycling via hydrogen-bonding-based affinity tags.

[Structure: see text] A novel procedure for catalyst recycling is described. Copper(I)-based catalysts, equipped with an affinity tag, are isolated from crude reaction mixtures on the basis of quadruple hydrogen-bonding interactions using a resin functionalized with complementary affinity tags. Recycled catalysts were successfully used to catalyze a tandem Sonogashira coupling/5-endo-dig cyclization and a Cu-catalyzed [3+2] Huisgen cycloaddition reaction in high yields.

Total synthesis and bioactivity of some naturally occurring pterulones.

The naturally occurring pterulones 1, 3, and 13 were synthesized in high overall yield from readily available methyl 3-(2-propenyl)-4-(2-propenyloxy)benzoate (6) by employing ring-closing metathesis (RCM) as a key step. The biological activities of the synthesized pterulones were tested using cells of Rhodotorulaglutinis and Saccharomyces cerevisiae.