[CH2:1]([C:4]1[C:13]([O:14][CH2:15][C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)=[CH:12][C:7]([C:8]([O:10][CH3:11])=[O:9])=[CH:6][C:5]=1[C:22]([O:24][CH3:25])=[O:23])[CH:2]=C.[O:26]=[O+][O-]>C(Cl)Cl.CO>[CH2:15]([O:14][C:13]1[C:4]([CH2:1][CH:2]=[O:26])=[C:5]([C:22]([O:24][CH3:25])=[O:23])[CH:6]=[C:7]([CH:12]=1)[C:8]([O:10][CH3:11])=[O:9])[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1A solution of dimethyl 4-allyl-5-(benzyloxy)isophthalate (3.5 g, 10.28 mmol) in CH2Cl2 and methanol was cooled to −78° C. and treated with ozone until the solution appeared blue (20 min). Nitrogen was bubbled through the solution until the blue color dissipated. Dimethylsulfide (1.0 mL) was added and the cold-bath was removed allowing the reaction mixture to warm to room temperature overnight. Concentration of the solution under vacuum provided an oil which was purified by column chromatography on silica gel eluted with 10-30% EtOAc in hexanes to afford the aldehyde (3.0 g, 98%) as a white solid. 1H NMR (300 MHz, CHLOROFORM-d) δ ppm 3.90 (s, 3 H) 3.95 (s, 3 H) 4.29 (s, 2 H) 5.14 (s, 2 H) 7.31-7.56 (m, 5 H) 7.81 (d, J=1.32 Hz, 1 H) 8.29 (d, J=1.51 Hz, 1 H) 9.75 (s, 1 H); MS (ESI, pos): 343.
Wird geladen…
