and the residue was dissolved in toluene the organic layer was separated washed with water 10 aqueous citric acid sat aq nahco 3 and dried over na 2 so 4 the organic layer was concentrated in vacuo and the residue was stripped with toluene yielding compound c2 14 272 g 0 708 mol 96 as a white solid compound c2 14 272 g 0 708 mol was dissolved in dcm 10 l under n 2 atmosphere zirconium chloride 758 g 3 25 mol was added which resulted in a yellow suspension the mixture was stirred at ambient temperature until the conversion was completed the reaction mixture was cooled to 3 u00b0 c before 200 g ice was added in batches water 2 l was added and the mixture was stirred at 4 u00b0 c for 1 hr then an additional amount of water 5 l was added the aqueous layer was separated and extracted with dcm the combined organic layers were filtered over na 2 so 4 and concentrated in vacuo the residue was stripped with toluene leaving a green residue the residue was dissolved in dcm and filtered over sio 2 leaving compound c2 15 255 g 0 663 mol 94 as an orange solid pd 10 on charcoal 120 g was suspended in water 800 ml under n 2 atmosphere t butanol 800 ml and a solution of compound c2 15 115 g 0 299 mol in thf 800 ml were added the mixture was applied to h 2 ambient pressure and stirred at ambient temperature until the.