Dichloromethane → 5-(4-Benzyloxy-benzyl)-2,2-dimethyl-[1,3]dioxolan-4-one

HRID 1985259Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1985259
[CH2:1]([O:8][C:9]1[CH:14]=[CH:13][C:12]([CH2:15][CH:16]([OH:20])[C:17]([OH:19])=[O:18])=[CH:11][CH:10]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.CO[C:23](OC)([CH3:25])[CH3:24].C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1.C(Cl)Cl>C(Cl)(Cl)Cl.O>[CH2:1]([O:8][C:9]1[CH:14]=[CH:13][C:12]([CH2:15][CH:16]2[O:20][C:23]([CH3:25])([CH3:24])[O:18][C:17]2=[O:19])=[CH:11][CH:10]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Komponenten

7

Edukt 4

HCID 6344DichloromethaneHCID 64952,2-DimethoxypropaneHCID 466102Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1)HCID 107073143-(4-(Benzyloxy)phenyl)-2-hydroxypropanoic acid

Produkt 1

HCID 184437075-(4-Benzyloxy-benzyl)-2,2-dimethyl-[1,3]dioxolan-4-oneAusbeute 88 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 962WaterLösungsmittelHCID 6212ChloroformLösungsmittel

Versuchsvorschrift

A mixture of 3-(4-benzyloxy-phenyl)-2-hydroxy-propionic acid (2.0 g, 7.34 mmol), 2,2-dimethoxypropane (18.63 g, 179 mmol) and pyridinium p-toluene sulfonate (0.92 g, 3.66 mmol) in CHCl3 (80 mL) was heated to reflux for 40 minutes under N2. The reaction was cooled and worked up extractively with CH2Cl2 and water. The organic layer was dried (Na2SO4) and the solvent removed in vacuo to afford crude product that was purified by flash chromatography using 10:1 hexanes:acetone to afford 2.01 g (88%) 5-(4-benzyloxy-benzyl)-2,2-dimethyl-[1,3]dioxolan-4-one. Rf=0.53 (1:1 hexanes:acetone). 1H NMR (500 MHz, CDCl3) δ 7.43-7.35 (m, 4H), 7.34-7.29 (m, 1H), 7.16 (d, 2H, J=8.80 Hz), 6.91 (d, 2H, J=8.80 Hz), 5.04 (s, 2H), 4.61 (dd, 1H, J=6.36 Hz, J=4.40 Hz), 3.13 (dd, 1H, J=14.67 Hz, J=4.40 Hz), 2.99 (dd, 1H, J=14.67 Hz, J=4.40 Hz), 1.50 (s, 3H), 1.36 (s, 3H); MS (ES+) Calc'd for C19H20O4 (M+NH4) 330. Found m/z 330 (100%).

Aufarbeitung

  1. temperaturewas heated
  2. temperatureto reflux for 40 minutes under N2
  3. temperatureThe reaction was cooled
  4. dry with materialThe organic layer was dried (Na2SO4)
  5. customthe solvent removed in vacuo
  6. customto afford crude product that
  7. customwas purified by flash chromatography

Quellen und Nachweise

ORD-Eintrag
ord-3e7bd06d41d04f5180f60bd5a5edc025
Quelldatensatz
uspto-grants-2009_06
Patentnummer
US07544812B2

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