반응 #620400

ord-228dc9dd05d94035bb55d4a1712b2cd5

반응 조건

상세 조건
See reaction.notes.procedure_details.

후처리

  1. 1
    온도cooled in an ice-bath
  2. 2
    온도, then heated
  3. 3
    온도under reflux for 3 h
  4. 4
    온도The mixture was cooled in an ice bath
  5. 5
    여과filtered through Celite
  6. 6
    세척the Celite washed with hot CHCl3 (3×)
  7. 7
    건조The combined filtrates were dried (MgSO4)
  8. 8
    여과filtered
  9. 9
    기타the solvent evaporated to a colourless oil
  10. 10
    기타The oil was chromatographed on silica gel (CH2Cl2-MeOH-28% aq. NH4OH, 96:4:0.5
  11. 11
    기타9:1:0.05) to give a pale yellow oil which
  12. 12
    workup.DISTILLATIONwas distilled on a Kugelrohr apparatus at 120° C./0.1 mmHg

실험 절차

Diethyl L-tartrate [(2R,3R)-diethyl 2,3-dihydroxysuccinate] was converted to (2S,3R)-diethyl 2-azido-3-hydroxysuccinate according to the literature method (A. Breuning, R. Vicik and T. Schirmeister, Tetrahedron: Asymm., 2003, 14, 3301) and then into (S)-ethyl 2-azido-2-((R)-2,2-dimethyl-1,3-dioxolan-4-yl)acetate according to the method described by S. Saito, T. Ishikawa, A. Kuroda, K. Koga and T. Moriwake, Tetrahedron, 1992, 48, 4067. This latter compound (1.8 g, 7.85 mmol) was dissolved in dry THF (12 ml) and cooled in an ice-bath. Lithium aluminium hydride (31.4 ml, 31.4 mmol, 1M in diethyl ether) was added and the mixture warmed to rt and stirred for 30 mins., then heated under reflux for 3 h. The mixture was cooled in an ice bath and water (1.2 ml), 15% aq. NaOH (1.2 ml), and water (4 ml) added successively. The mixture was diluted with diethyl ether, filtered through Celite and the Celite washed with hot CHCl3 (3×). The combined filtrates were dried (MgSO4), filtered and the solvent evaporated to a colourless oil. The oil was chromatographed on silica gel (CH2Cl2-MeOH-28% aq. NH4OH, 96:4:0.5 then 9:1:0.05) to give a pale yellow oil which was distilled on a Kugelrohr apparatus at 120° C./0.1 mmHg to afford (R)-2-amino-2-((R)-2,2-dimethyl-1,3-dioxolan-4-yl)ethanol (0.415 g, 61%) as a colourless oil. 1H NMR (CDCl3, referenced to the centre line of CDCl3 at 77.0 ppm) δ 4.10-3.98 (m, 2H), 3.87 (dd, J=7.4, 5.7 Hz, 1H), 3.71 (dd, J=10.9, 4.4 Hz, 1H), 3.54 (dd, J=10.9, 5.7 Hz, 1H), 2.95 (m, 1H), 1.94 (brs, 3H, exchanged to D2O), 1.42 (s, 3H), 1.35 (s, 3H). 13C NMR (CDCl3) δ 109.0, 77.8, 66.5, 64.4, 54.6, 26.5, 25.2. +ESMS Found 162.1130 (M+H)+ C7H16NO3 requires 162.1130. [α]D20 −9.5 (c, 1.47, CHCl3). Lit., [α]D −10.5, c 1.5, CHCl3 for the product made from D-ascorbic acid according to M. Banwell, C. De Savi, D. Hockless and K. Watson, Chem. Commun., 1998, 645.

출처

DOI: 10.6084/m9.figshare.5104873.v1특허: US08853224B2uspto-grants-2014_10