“…The crude reaction product was purified by Kugelrohr giving ( R )- 1a (90 mg, 83%, ee = 98%, GC) as oil. Spectral data were identical to those reported in literature: IR (neat) ν max (cm -1 ) 1758 stretching CO (lit 12c. 1750); [α] D = +518 ( c = 0.26, CHCl 3 ); 1 H NMR (CDCl 3 , 400 MHz) δ 6.57 (1H, m), 6.22 (2H, m), 4.10 (1H, d, J = 3.5 Hz), 3.33 (1H, m), 3.22 (1H, m), 2.38 (1H, dm, J = 10.2 Hz), 2.07 (1H, dm, J = 10.2 Hz); 13 C NMR (CDCl 3 , 100 MHz) δ 206.8, 140.7, 131.3, 56.9, 54.6, 46.2, 45.8; MS (EI, 70 eV) m / z 142 (M + , 40), 113 (6), 79 (100), 66 (75), 51 (45) 39 (55).…”