[structure: see text] Callyberynes A and B, polyacetylenic hydrocarbons from Callyspongia sp., have been synthesized for the first time using highly convergent approaches based on optimized Cadiot-Chodkiewicz (Alami, Vasella) and sequential Sonogashira cross-coupling reactions.
Efficient total syntheses of the sponge-derived hydrocarbon polyacetylenes callyberynes A-C have been achieved using metal-catalyzed cross-coupling reactions of highly unsaturated 1,3-diyne fragments as the key steps, namely: Cadiot-Chodkiewicz reaction under Alamis optimized conditions (sp-sp), sequential Sonogashira reaction of a cis,cis-divinyl dihalide (sp(2)-sp), and Kumada-Corriu reaction of an unactivated alkyl iodide (sp(3)-sp). This last approach constitutes the first application of a metalcatalyzed sp(3)-sp Kumada-Corriu cross-coupling reaction to the synthesis of a natural product.