Part 1 - Silylation: Ketone 13 is dissolved in DMF.  Imidazole and TBSCL are added at 22°C and the reaction mixture is stirred for one hour before being diluted with diethyl ether and quenched with aqueous sodium bicarbonate.  This mixture is extracted with diethyl ether, washed with brine, and dried over sodium sulfate.  The remaining residue is purified by flash column chromatography.

Part 2 - Wittig Methylenation: Ph3PCH3+I- is dissolved in THF and n-BuLi is added at -78°C.  The resulting mixture is allowed to warm to 0°C and stirred at that temperature for 30 minutes before adding the product from part 1 dissolved in THF.  The reaction mixture is stirred at 0°C for 30 minutes before it is quenched with aqueous sodium bicarbonate.  The product is extracted with diethyl ether, washed with brine, and dried over sodium sulfate.  The remaining residue is filtered and concentrated under vacuum and purified through flash column chromatography.

Part 3 - Desilylation: The product from part 2 is dissolved in THF and TBAF dissolved in THF is added at 22°C.  The resulting mixture is stirred at 22°C for 1 hour before being quenched with aqueous sodium bicarbonate.  The mixture is extracted with ethyl acetate, washed with brine, and dried over sodium sulfate.  The remaining residue is filtered, the solvent is evaporated, and it is purified with flash column chromatography.

Part 4 - Oxidization with DMP: The product from part 3 is added to CH2Cl2 and Dess-Martin periodinane is added at 0°C.  The mixture is stirred at 0°C for one hour, at which point it is quenched with aqueous sodium bicarbonate.  This mixture is extracted with ethyl acetate and dried over sodium sulfate.  The remaining residue is filtered and the solvent is removed under vacuum.  Product 19 is purified from the residue with flash column chromatography.