[loklok]

I have tried several conditions of the RCM with a mono subs. terminal alkene and a,b-unsaturated ketone. If the RCM proceeded, the product should be a macro cyclic enone. But everytime i get back the starting material and no reaction proceeded even i added more of the catalyst or evaluated the temp. I did not perform the reaction in a drybox or using Schlenk glasswares, I just performed it under Argon. I wonder if this is the reason of the failure of RCM. Please give some comments about the reaction or the reaction conditions. Thanks.

[sjb]

What ring size are you looking at forming? Which system are you using? Some have problems due to chelation or similar of carbonyls to the active centre, if I recall correctly.

[StarvinMarvin]

You may try under high dilution conditions. You can search for some papers by my supervisor Karl J. Hale. Or you can give me your email on PM so that I could send you some of his papers in which he did final steps of total syntheses of Bryostatin and Azinothricin via RCM. But as I recall, the yields of such reactions are never great. If you reach 40% you'd do great.

[gfunk]

Which catalysts have you tried?  Perhaps look into relay RCM?