A variety of inter- and intramolecular dehydration was found in the reactions of [{Ru(P(OCH3)(3))(2)-(CH3CN)(3)}(2)(mu-S-2)](CF3SO3)(4) (1) with hydroxyl substituted alkenes and alkynes. Treatment of 1 with allyl alcohol gave a C3S2 five-membered ring complex, [{Ru(P(OCH3)(3))(2)(CH3CN)(3)}(2){mu-SCH2CH2CH(OCH2CH = CH2)S}](CF3SO3)(4) (2), via C-S bond formation after C-H bond activation and intermolecular dehydration. On the other hand, intramolecular dehydration was observed in the reaction of 1 with 3-buten-1-ol giving a C4S2 six-membered ring complex, [{Ru(P(OCH3)(3))(2)(CH3CN)(3)}(2) {mu-SCH2CH=CHCH2S}](CF3SO3)(4) (3). Complex 1 reacts with 2-propyn-1-ol or 2-butyn-1-ol to give homocoupling products, [{Ru(P(OCH3)(3))(2)(CH3-CN)(3)}(2){mu-SCR=CHCH(OCH(2)CdropCR)S}](CF3SO3)(4) (4: R = H, 5: R = CH3), via intermolecular dehydration. In the reaction with 2-propyn-1-ol, the intermediate complex having a hydroxyl group, [{Ru(P(OCH3)(3))(2)(CH3CN)(3)}(2){mu-SCH=CHCH(OH)S}](CF3SO3)(4) (6), was isolated, which further reacted with 2-propyn-1-ol and 2-butyn-1-ol to give 4 and a cross-coupling product, [{Ru(P(OCH3)(3))(2)(CH3CN)(3)}(2){mu-SCH=CHCH-(OCH(2)CdropCCH(3))S}](CF3SO3)(4) (7), respectively. The reaction of 1 with diols, (HO)CHRC-CCHR(OH), gave furyl complexes, [{Ru(P(OCH3)(3))(2)(CH3CN)(3)}(2){mu-SSC=CROCR=CH}](CF3SO3)(3) (8: R = H, 9: R = CH3) via intramolecular elimination of a H2O molecule and a H+. Even though (HO)(H3C)(2)CC=CC(CH3)(2)(OH) does not have any propargylic C-H bond, it also reacts with 1 to give[{Ru(P(OCH3)(3))(2)(CH3CN)(3)}(2){mu-SCH2C(=CH2)C( C=C(CH3)(2))}S](CF3SO3)(4) (10). In addition, the reaction of 1 with (CH3O)(H3C)(2)CC= CC(CH3)(2)(OCH3) gives [{Ru(P(OCH3)(3))(2)(CH3CN)(2)}{mu-S C(C(CH3)(2)OCH3)C=CC(CH3)CH2S}{Ru(P(OCH3)(3))(2)(CH3CN)(3)}](CF 3SO3)(4) (11), in which one molecule of CH3OLH is eliminated, and the S-S bond is cleaved.