Acetone → HCID 54354149, compound

Participants

Reaction Steps

A solution of 4-allylazetidin-2-one (0.25 g) in dry tetrahydrofuran (25 ml) was stirred at -5° C. under argon and treated with a 2.5 M solution of n-butyl-lithium in hexane (3.0 ml). A period of 1 hour was allowed for the dianion to form and dry acetone (1.0 ml) was then added. After a further 10 mins. water (5 ml) was added to the reaction mixture, which was then concentrated to about 10 ml in volume. This was extracted with methylene chloride (20 ml), and the organic phase was then dried over sodium sulphate and concentrated. The residue was chromatographed on silica gel 60 (<230 mesh) eluting with ethyl acetate/60°-80° petroleum ether 1:1 grading to ethyl acetate to give the cis and trans aldol products. The least polar isomer was cis-4-allyl-3-(2-hydroxy-2-propylazetidin)2-one (0.029 g); m.p. 144° (ethyl acetate/60°-80° petroleum ether). ν max (CHCl3) 3400, 2980, 2930, 1745 and 1640 cm-1 ; δ(CDCl3) 1.35 (3H, s), 1.51 (3H, s), 2.18 (1H, br), 2.5-2.9 (2H, m), 3.28 (1H, d, J 5 Hz), 3.85 (1H, td J 9 and 5 Hz), 4.9-6.1 (3H, m), and 7.20 (1H, br) (Found: C, 64.2; H, 9.0; N, 8.2%. C9H15NO2 requires C, 63.9; H, 8.9 and N, 8.3%). The more polar isomer was trans-4-allyl-3-(2-hydroxy-2-propyl)azetidin-2-one (0.042 g); νmax (CHCl3) 3400, 2980, 2930, 1750 and 1640 cm-1, δ(CDCl3) 1.29 (3H, s), 1.39 (3H, s), 2.41 (3H, br t J 6 Hz), 2.88 (1H, d, J 2 Hz), 3.69 (1, 6d J 6 and 2 Hz), 4.9-5.4 (2H, m), 5.89 (1H, ddt J 18, 9 and 6 Hz), and 6.50 (1H, br).

Provenance & Evidence