Acetaldehyde → Isohexane ethyl acetate

Participants

Reaction Steps

To a stirred solution of (4R,9aR)-6-bromo-4-methyl-1,2,3,4,9,9a-hexahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester (1.0 g) in dry tetrahydrofuran (30 mL) at −78° C. under argon was added dropwise a solution of butyl lithium in hexanes (2.5M, 1.2 mL). The mixture was stirred for 1 h then acetaldehyde (0.31 mL) was added dropwise. The mixture was warmed to room temperature, stirred for 30 minutes then partitioned between ethyl acetate (50 mL) and aqueous ammonium chloride solution (50 mL). The organic layer was washed (water), treated with di-tert-butyl dicarbonate (0.5 g), left to stand for 30 minutes then concentrated in vacuo. The residue was purified by flash column chromatography [SiO2; isohexane-ethyl acetate (9:1)→>(1:1)] to give (4R,9aR)-6-(1(RS)-ethanol)-iodo-4-methyl-1,2,3,4,9,9a-hexahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester as a clear oil (0.43 g), NMR δH (400 MHz, CDCl3) 7.13 (1H, dd, J 7.5, 1 Hz), 6.33 (1H, d, J 7.5 Hz), 4.69 (1H, q, J 6.5 Hz), 4.36 (1H, m), 4.29–3.81 (4H, m), 3.06 (1H, m), 3.01 (1H, dd, J8.5, 8.0 Hz), 2.66 (1H, m ), 2.51 (1H, dd, J 16, 6 Hz), 1.48 (9H, s), 1.44 (3H, d, J 6.5 Hz) and 1.24 (3H, dt, J 6.5, 4 Hz); m/z M+ 334 (M+1).

Provenance & Evidence