Enantiomerically pure 1-(1Z,3E)-sulfinyl iron(0) dienols have been elaborated to bis-olefins capable of undergoing ring-closing metathesis chemistry. Using Grubbs' ruthenium carbene catalyst, a six-membered carbocycle (with one chiral center) and seven-, eight-, and nine-membered carbocycles (with two chiral centers) have been prepared. Novel transformations include the LiClO4-promoted allylation of an alkylidene malonate and a reductive sulfur−carbon bond cleavage to convert a vinyl sulfoxide into an alkene with SmI2.