Reaction Steps
A 1 M solution of lithium aluminium hydride (122 mL, 122 mmol) was added via cannula to a stirred solution of crude ester 11 (44 g), prepared according to Example 10, in dry ether (150 mL). The mixture was stirred for 2 h at room temperature under nitrogen, cooled to 0° C. and water (9 mL) was added dropwise with stirring, followed by 15% NaOH (9 mL) and water (27 mL), which was added dropwise at 0° C. to produce a white precipitate. The precipitate was filtered and washed with ether (2×50 mL). The filtrate was dried over MgSO4. The residue, obtained upon concentration, was subjected to column chromatography on silica gel. Contaminant benzyloxy-2-ethoxy ethanol (12.4 g) was first eluted with ether/hexane (2:1) while the alcohol 12(24 g, 59% based on diethyl allylmalonate) was eluted with 2% methanol in ether. IR (KBr) νmax 3404, 3071, 3033, 2930, 2868, 1640, 1498, 1454, 1361, 1202, 1100, 1042, 996, 916, 838, 697 cm−1; 1HNMR (CDCl3) δ 1.63-1.73 (m, 3 H), 2.02-2.15 (m, 2 H), 2.84 (t, J=5.8 Hz, 1 H), 3.45-3.58 (m, 4 H), 4.49 (s, 2 H), 5.00-5.03 (m, 2 H), 5.70-5.85 (m, 1 H), 7.26-7.35 (m, 5 H); 13CNMR (CDCl3) δ 31.65, 3620, 3891, 53.36, 65.58, 68.66, 73.13, 116.28, 127.69, 127.71, 128.39, 136.75, 137.88: mass spectrum (EI), m/z (rel intensity) 263 (M++1.10), 203 (1.5), 185 (2.3), 181 (3.5), 143 (2.5), 129 (5), 111 (6), 108 (6), 107 (22), 95 (5), 93 (6), 92 (12), 91 (100), 81 (16), 79 (10), 77 (5), 67 (10), 65 (13).
