“…(28 mg, 70%), colorless oil. R f 0.60 (1:1 hexanes/ethyl acetate); [a] D 20 -71.56 (c 0.93, CHCl 3 ); IR (film): n 2976, 2954, 2938, 1750, 1734, 1732, 14337, 1372, 11240, 1221, 1195 cm -1 ; 1 H NMR (600 MHz, CDCl 3 ) d 5.40 (m, 1H), 4.93 (dd, J = 7.9, J = 2.6 Hz, 1H), 4.69 (t, J = 4.9 Hz, 1H), 4.23 (dd, J = 8.0, J = 5.0 Hz, 1H), 3.78 (s, 3H), 3.13 (dt, J = 12.8, J = 4.5 Hz, 1H), 2.21 (dt, J = 14.9, J = 12.9 Hz, 1H), 2.12-2.06 (m, 4H), 1.52 (s, 3H), 1.38 (s, 3H) ppm; 13 C NMR (150 MHz, CDCl 3 ) d 171.4, 170.3, 169.7, 109.9, 75.5, 73.9, 7.1, 68.7, 52.2, 38.11, 27.9, 26.2, 24.9, 20.9 ppm; MS (EI) m/z (%): 313 (M + -CH 3 , 13), 241 (15), 171 (23), 153(47), 43(100); HRMS (M + -CH 3 ) calcd for C 14 H 19 O 8 315.1080, found 315.1082.…”