The utility of intra- and intermolecular olefin metathesis in total synthesis has been well established. Herein we present (1) tandem cross-metathesis/Wittig or Horner-Wadsworth-Emmons olefination methodology for the stereoselective synthesis of both (2E,4E)- and (2Z,4E)-dienoates; and (2) an efficient strategy for natural product synthesis which sequences allyl- or crotylmetallation reactions with olefin cross metathesis. Application of the latter towards a concise total synthesis of (+)-crocacin C will be discussed.