In this paper, the synthesis of each necessary components for the Wittig coupling reaction, aldehydes and phosphonium salts, is presented. In the last years the Wittig reactions began to have a crucial role in the field of retinoids’ chemistry. The diversity of possible reactants brought a specific interest on these compounds. Obtaining of the anhydride by using a protective group TBDPSiCl and the 4-oxo-ß-ionone through the oxidation of the ß-ionone with PCC is presented. The tert-BDPSi group offers a unique and novel device that represents a significant improvement concerning the existing groups: the primary alcohol groups are preferentially transformed into secondary siloxane groups. This group has unique stability properties compared with other protective groups, being not affected by the hydrogenolysis conditions, unlike siliconed ethers, sensitive to hydrogenolysis. The DMSO was activated by oxalyl chloride (Swern oxidation) at about - 60°C, by loosing CO2 and CO in order to form a sulfonium chloride salt. The resulting agent is better than the DMSO- anhydrous trifluoroacetic acid. The following analyzing techniques have been used: plates and column chromatographical separation, melting point measurement, RMN, IR and mass spectroscopy.
