[H-].[Al+3].[Li+].[H-].[H-].[H-].[Br:7][C:8](=[CH2:19])[CH2:9][CH:10]([C:15](OC)=[O:16])[C:11](OC)=[O:12].C([O-])(=O)CC([O-])=O>C(OCC)C>[Br:7][C:8](=[CH2:19])[CH2:9][CH:10]([CH2:15][OH:16])[CH2:11][OH:12]Lithium aluminum hydride (1.9 g, 7.65 mmol) was slurried in anhydrous diethyl ether (50 ml) and cooled to −78° C. in a dry ice/acetone bath. A solution of the product from step A (0.639 g, 16.84 mmol) in dry ether (26 ml) was then added dropwise. After the malonate was added, the solution was allowed warm to room temperature and stirring was continued for 3 hours. The reaction was quenched with brine (50 ml), extracted with ethyl acetate (3×25 ml) and dried over MgSO4. The solvent was removed in vacuo to give the desired product (1.3 g, 86%) which was used for the next step without further purification. 1H-NMR (300 MHz, CDCl3) δ 5.66 (d, J=1.2 Hz, 1H), 5.48 (d, J=1.5 Hz, 1H), 3.86 (m, 2H), 3.73 (m, 2H), 2.51 (d, J=7.5 Hz, 2H), 2.40 (br s, 2H), 2.15 (m, 1H).
Wird geladen…
