[Br-].[C:2]([CH2:5][CH2:6][CH2:7][CH2:8][P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)([OH:4])=[O:3].[Na].O[CH:30]1[CH2:39][C:38]2[C:33](=[CH:34][CH:35]=[CH:36][CH:37]=2)[CH2:32][O:31]1>CS(C)=O>[OH:31][CH2:32][C:33]1[CH:34]=[CH:35][CH:36]=[CH:37][C:38]=1/[CH:39]=[CH:30]/[CH2:8][CH2:7][CH2:6][CH2:5][C:2]([OH:4])=[O:3]To a solution of 60.2 g. of 4-carboxybutyltriphenylphosphonium bromide in 200 ml. of dimethylsulfoxide is added a solution of the sodium salt of dimethylsulfoxide. The solution is stirred for one hour and 6.8 g. of 3-hydroxyisochromane in 25 ml. of dimethylsulfoxide is added. The solution is stirred at room temperature for 40 hours and then poured into 1200 ml. of ice water and filtered. The filtrate is washed with ether-ethyl acetate (1:1) and acidified to pH2 with oxalic acid. The mixture is again filtered and the filtrate is extracted with ether-pentane (2:1). The extract is washed with brine, dried, concentrated, and the solid recrystallized from toluene to yield 7-(2-hydroxymethylphenyl)trans-6-heptenoic acid as white crystals having a melting point of 92°-94.5° C.
Loading…