[Si](OC[C@H]1OC(=O)C[C@@H]1C1OCCO1)(C(C)(C)C)(C)C.[H-].[H-].[H-].[H-].[Li+].[Al+3].O1CCO[CH:28]1[C@@H:32]([CH2:37][CH2:38][OH:39])[C@H:33]([OH:36])[CH2:34][OH:35].C1COCC1.O>C1COCC1.C(Cl)Cl.CO.C(CO)C>[OH:36][C@H:33]1[C@H:32]2[C@H:28]([O:39][CH2:38][CH2:37]2)[O:35][CH2:34]1According to the above general procedure, a solution containing 216 mg (0.714 mmol) (4S,5S)-5-(tert-butyldimethylsilanyloxymethyl)-4-[1,3]-dioxolan-2-yldihydrofuran-2-one (3a) in THF (25 mL) was reduced with 98 mg (2.58 mmol) LiAlH4 in THF (7 mL) to give the crude protected triol (4) (132 mg, 96%). The crude triol (4) (76 mg (0.40 mmol)) was cyclized in 6 mL acidified THF:water (5:1). Column chromatography (silica gel 20 g, ethyl methanol in CH2Cl2 10%) gave compound (5) (37.6 mg, 84%) as a colorless solid, Rf=0.35, [α]25D −25°, c 1.0, MeOH. 1H-NMR (400 MHz, CDCl3) δ: 1.67 (mc, 1H), 2.14 (mc, 1H), 2.63 (bs, 1H), 2.79 (mc, 1H), 3.75-3.88 (m, 3H), 3.94 (dd, 1H, J=3.0 Hz, J=10.2 Hz), 4.20 (d, 1H, J=2.7 Hz), 5.86 (d, 1H, J=4.9 Hz). 13C-NMR (125.8 MHz, CDCl3, Dept) δ: 29.19 (−), 52.38 (+), 69.52 (−), 75.60 (−), 78.14 (=), 109.23 (+). C6H10O3; Exact Mass: 130.06; Mol. Wt.: 130.14; C, 55.37; H, 7.74; O, 36.88.
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