C(OC[C@H]1OC(=O)C[C@@H]1C1OCCO1)(=O)C.[H-].[H-].[H-].[H-].[Li+].[Al+3].O1CCO[CH:24]1[C@@H:28]([CH2:33][CH2:34][OH:35])[C@H:29]([OH:32])[CH2:30][OH:31].C(CO)C>CCOCC.C1COCC1.CCOCC.C1COCC1.O.Cl.C(Cl)(Cl)Cl.O1CCOC1[C@@H](CCO)[C@H](O)CO.CO>[OH:32][C@H:29]1[C@H:28]2[C@H:24]([O:35][CH2:34][CH2:33]2)[O:31][CH2:30]1According to the above general procedure, a solution containing 1.44 mg (6.26 mmol) (4S,5S)-5-(acetyloxymethyl)-4-[1,3]dioxolan-2-yldihydrofuran-2-one (3c) in Et2O:THF 1:1 (20 mL) was reduced with 522 mg (13.75 mmol) LiAlH4 in Et2O (100 mL) to give the crude protected triol (4) (1.12 mg, 93%). The crude triol (4) was cyclized in 60 mL THF water (5:1) and 5 mL 1N hydrochloric acid. Column chromatography (silica gel 20 g, ethyl methanol in CHCl3 10%) gave compound (5) (515 mg, 64%) as a colorless solid, Rf=0.35, [α]25D −25.1°, c 1.0, MeOH.
Wird geladen…
