... Tetrahedron: Asymmetry. ... The ethereal solution was concentrated to a volume of 100 mL and slowly cooled to 0°C, and the product was allowed to crystallize ... 1.09 (m, 1H), 1.15–1.19 (m, 4H, including d, 3H, J=7.1 Hz), 1.6 (m, 1H), 1.7 (m, 1H), 2.64 (m, 1H), 3.76 (m, 1H); 13 C NMR ...