HCID 178476815, compound → HCID 178511511, compound

Participants

Reaction Steps

A solution of (±)-cis-ethyl [3-(t-butyloxycarbonyl)aminocyclopentanyl]butylphosphinate (14) (1.07 g, 3.21 mmol) was dissolved in aqueous HCl (6 M, 40 cm3) and the solution heated at reflux for 30 hours. After cooling, the solution was evaporated to dryness under reduced pressure. The residue was dissolved in water (10 cm3) and applied to an ion exchange column (Dowex 50, H+). The column was eluted with water until the eluate was colourless and the pH 7. On further elution with aqueous pyridine (1 M), ninhydrin positive fractions were collected and the solvent removed in vacuo. Residual traces of pyridine were removed by repeatedly redissolving the compound in water (20 cm3) and re-evaporating (3 times). Recrystallisation from ethanol/acetone followed by drying gave the desired title compound (15) as an off white solid (450 mg, 68%, m.p. (dec.) 180-183° C.): 1H-NMR (300 MHz, D2O) δH 0.68 (3H, 2×d, J=6.9 and 7.2 Hz, PCH2CH2CH2CH3),1.02-2.43 (13H, m, C(1)—H, C(2)—H, C(2)—H′, C(4)—H, C(4)—H′, C(5)—H and C(5)—H′, PCH2CH2CH2CH3, PCH2CH2CH2CH3,PCH2CH2CH2CH3),3.56 (1H, m, C(3)—H); 13C-NMR (75 MHz, D2O) δC 13.46 (s, PCH2CH2CH2CH3), 24.11 and 24.31 (d, 3JPC=15.17 Hz, PCH2CH2CH2CH3), 24.31 (s, C(5)), 24.53 and 24.56 (d, 2JPC=2.87 Hz, PCH2CH2CH2CH3), 27.96 and 29.17 (d, JPC=91.32 Hz, PCH2CH2CH2CH3),31.12 and 31.20 (d, 2JPC=6.3 Hz, C(2)), 31.95 (s, C(4)), 36.14 and 37.38 (d, JPC=93.33 Hz, C(1)), 52.97 and 52.88 (d, 3JPC=7.15 Hz, C(3)); 31P-NMR (121MHz, D2O) δP 50.74; MS (ESI) m/z 205.9 (37%) (MH+), 411.3 (100), 484.3 (14), 102.4 (12).

Provenance & Evidence