Alkyne metathesis is an organic reaction involving the redistribution of alkyne chemical bonds. [1] This reaction is closely related to olefin metathesis. Ring Closing Metathesis (RCM) The Ring-Closing Metathesis (RCM) allows synthesis of 5- up to 30-membered cyclic alkenes. The E/Z-selectivity depends on the ring strain. Ring Closing Alkyne Metathesis (RCAM) in Natural Product total Synthesis CCH2 CCH2. Alkyne Activity in Metathesis Reactions RCAM in the presence of Alkene A concise and stereoselective synthesis of the macrocyclic musk civetone 6 is reported starting from readily available 9-undecynol. The key steps comprise a rin Alkyne metathesis has been a useful tool for C–C bond formation since the discovery of structurally well-defined metal alkylidynes by Schrock and coworkers. 2 These. ChemInform Abstract: Novel and Flexible Entries into Prostaglandins and Analogues Based on Ring Closing Alkyne Metathesis or Alkyne Cross Metathesis. Ring-closing metathesis, or RCM, is a widely used variation of olefin metathesis in organic chemistry for the synthesis of various unsaturated rings via the. Enyne Metathesis. The Enyne Metathesis is a ruthenium-catalyzed bond reorganization reaction between alkynes and alkenes to produce 1,3-dienes. Information regarding ring-closing metathesis; an essential tool for C-C bond formation as shown by the profound impact on total synthesis; provided by Sigma-Aldrich.com. ALKYNE METATHESIS CATALYSTS cheap air stable user friendly harsh slow limited compatibility expensive laborious (highly) sensitive (O 2, H 2 O, N 2) short lifetimes.