The thermal reaction Of Ru3(CO)12 with (+/-) 7-oxabicyclo[2.2.1]hept-5-en-2-one (+/-)-2, (+/-) 7-oxabicyclo[2.2.1]hept-5-en-2-endo-ol 21 and the corresponding benzoate 22 afforded the [Ru3H2(CO)9 (7-oxabicyclo[2.2.1]hept-5-yn-2-yl)] clusters 13, 19 and 20, respectively. Treatment of 13, 19 and 20 with triphenylphosphine and Me3NO led to the corresponding Ru3H2(CO)6 (Ph3P)3 (mu3-eta2-7-oxabicyclo[2.2.1]hept-5-yn-2-yl) complexes 17, 23 and 24, respectively, in which each of the ruthenium metallic centres bears one Ph3P ligand. Single crystal diffraction studies of di(mu-hydrido)(7-oxabicyclo[2.2.1]hept-5-yn-2-one)-triangulo-tris(tricar bonylruthenium)(3Ru-Ru) 13 and of di(mu-hydrido) (7-oxabicyclo[2.2.1]hept-5-yn-2-one)-triangulo-tris[dicarbonyl(triphenyl phosphine]ruthenium)(3Ru-Ru) 17 are reported. Preliminary studies on the reactivity of these new clusters are described; treatment of the complex 20 derived from 7-oxabicyclo[2.2.1]hept-5-en-2-endo-yl benzoate with (CH3)3SiOSO2CF3 gave a mixture of [RU3H2(CO)9(benzyne)] 25 and [RU3H2(CO)9(C6H3-OCO-C6H5)] 26.