[CH2:1]([C:6]1([C:19]([O:21][CH3:22])=[O:20])[CH2:11][CH2:10][N:9]([C:12]([O:14][C:15]([CH3:18])([CH3:17])[CH3:16])=[O:13])[CH2:8][CH2:7]1)[CH2:2][CH2:3][CH:4]=C.CSC.C[OH:27]>>[O:27]=[CH:4][CH2:3][CH2:2][CH2:1][C:6]1([C:19]([O:21][CH3:22])=[O:20])[CH2:11][CH2:10][N:9]([C:12]([O:14][C:15]([CH3:16])([CH3:18])[CH3:17])=[O:13])[CH2:8][CH2:7]1A solution of methyl 4-(pent-4-en-1-yl)-1-(tert-butoxycarbonyl)piperidine-4-carboxylate (29.4 g, 0.0945 mol) from Step B in methanol (1000 mL) was cooled to −78° C. in a dry ice/methanol bath and ozone was bubbled into the solution until a blue color persisted. The excess ozone was removed with a stream of nitrogen and then methyl sulfide (69 mL, 0.95 mol) was added, the cooling bath was removed, and the reaction mixture was allowed to warm to room temperature over 1.5 h. The reaction mixture was then concentrated. The residue was then purified by flash chromatography eluting with 2:1 heptane/ethyl acetate to afford the title compound (23.0 g).
読み込み中…