Acetic Acid → HCID 11088170, compound

Participants

Reaction Steps

Glacial acetic acid (0.4 mL) and one drop of methanesulfonic acid were added to a solution of (5S)-5-(N,N-dibenzylamino)-4-hydroxy-hexanoic acid-tert-butyl ester (0.6 g, 1.57 mmol) in dry toluene (15.0 mL) in a 50 mL round bottom flask fitted with a reflux condenser. The reaction mixture was heated at reflux for 12 hours and then cooled to ambient temperature. The pH of the solution was adjusted to 7 by slow addition of a saturated solution of NaHCO3. The organic layer was separated, and the aqueous layer was extracted with Et2O (10 mL). The combined organic extracts were dried over MgSO4, filtered, and the solvent was removed in vacuo. The residue thus obtained was purified by flash column chromatography on silica gel with 4:1 hexanes/ethyl acetate to obtain 0.41 g (85% yield) of pure (5S)-5[(1S)-1-(N,N-dibenzylamino)-ethyl]-dihydrofuran-2(3H)-one (5a). White solid, mp. 61°-62° C., 1H NMR (300.15) δ1-11 (d, J=6.6 Hz, 3H), 1.83-2.15 (m, 2H), 2.44-2.50 (m, 2 2.86 (pentet, J=6.9 Hz, 1H), 3.71 (ABq, δA =3.87, δB =3.56, JAB=13.8 Hz, 4H), 4.49 (pentet, J=7.2 Hz, 1H), 7.10-7.41 (m, 10H); 13C NMR (75.8 MHz) 10.9, 25.6, 28.7, 54.3, 55.8, 83.1, 126.8, 128.2, 128.7, 139.9, 177.1; MS (10W res.) 310 (M+1, 20%), 224 (MeCHNBn2, 40%), 91 (NBn2, 100%); HRMS for C20H24NO2 : 310. 1807 (calc'd 310.1801); Anal calc'd for C20H23NO2 : C 77.64, H 7.49, N 4.53; Found: 77.54, H 7.55, N 4.49.

Provenance & Evidence