Ring closing metathesis (RCM) using Grubbs’ 1st generation catalyst with cis-[L2Pt(CH2CH2CH═CH2)(CH2CH2CH2CH═CH2)] yields a platinacyclooctene which can be hydrogenated to the platinacyclooctane, L2Pt(CH2)7 [L2 = Ph2PCH2CH2CH2PPh2 (dppp) or Ph2PCH2CH2PPh2 (dppe)] in high yield. © 2008 The Royal Society of Chemistry.