Reaktionsschritte
A mixture of diester 2 (40 g, 155 mmol), prepared according to Example 1, and lithium chloride (13 g, 300 mmol) in DMSO (100 mL). DMF (20 mL), and water (2 mL) was heated to 170° C. for 6 h and cooled to room temperature. The mixture was poured into water (250 mL), extracted with CH2Cl2 (3×100 mL), and dried over MgSO4. The solvent was removed under reduced pressure to afford the monoester ether 3 (25.2 g, 87%); IR (KBr) υmax 3079, 2974, 2921, 2869, 1732, 1640, 1461, 1443, 1470, 1374, 1177, 1121, 1029, 990, 916, 855 cm−1; 1HNMR (CDCl3) δ1.25 (t, J=7.05 Hz, 3H), 1.65-1.75 (m, 1H), 1.85-1.95 (m, 1H), 2.20-2.40 (m, 2H), 2.50-2.60 (m, 1H), 3.30 (s, 3H), 3.35-3.45 (m, 2H), 4.13 (q, J=7.05, 2H), 5.00-5.07 (dd, J=10.2, 25 Hz, 2H), 5.71-5.74 (m, 1H); 13CNMR (CDCl3) δ14.21, 31.44, 36.45, 42.12, 58.48, 60.12, 70.37, 70.38, 116.79, 135.19, 175.19; mass spectrum (EI), m/Z (rel intensity) 223 (11), 200 (19), 185 (M-1, 4.5), 154 (19), 153 (46), 143 (33), 128 (33), 121 (37), 120 (34), 112 (22), 108 (88), 95 (28), 82 (41), 81 (98), 79 (94), 59 (38), 57 (71), 55 (100), 54 (38), 53 (59),
