Wittig reaction sidechain

In traditional synthetic organic chemistry, the Wittig reaction plays an important role in carbon-carbon bond extension from the carbonyl group. CM is an attractive alternative for carbon-carbon extension from a terminal alkene. In fact, a pyrroh-dine ring of anthramycin derivative 55 has been constructed by RCM of 52, and the sidechain has been extended by CM of terminal alkene of 54 with ethyl acrylate. " In the CM, ruthenium carbene complex Ij, reported by Blechert, gives a good result since the ligand of the catalyst easily dissociated from the ruthenium metal at room temperature ... 

Carboprostacyclin, 43, a stable and biologically active analogue of prostacyclin (PGI2) provides an additional example of the utility of the Weiss-Cook reaction. The Weiss-Cook reaction product 41 was transformed into the advanced intermediate 42. A Wadsworth-Homer-Emmons reaction provided a method to append the alcohol sidechain to the aldehyde moiety and a Wittig reaction, on the deprotected ketone, introduced the carboxy sidechain for the desired target 43. 

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