Reaktion #2200582

Reaktionsgleichung

water

(2R,3S)-2-methyl-3-tetrahydropyranyloxybutanol

Et3N

ether

→

(2S,3S)-2-methyl-3-tetrahydropyranyloxybutyraldehyde

Ausbeute 101.0%

Lösungsmittel

DMSO

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITat room temperature for 1 hour
2. 2
   ExtraktionThe aqueous layer was extracted with ether
3. 3
   WaschenThe combined ether extracts were washed with 1M HCl, water, saturated NaHCO3, brine, and they
4. 4
   Trocknenwere dried over Na2SO4
5. 5
   Sonstigeevaporated in order

Vorschrift

The Py.SO3 complex (7.06 g, 44.36 mmol) was added in portions at 0° C. to a solution of (2R,3S)-2-methyl-3-tetrahydropyranyloxybutanol (5) (1.39 g, 7.39 mmol) and anhydrous Et3N (4.94 g, 6.78 ml, 48.77 mmol) in DMSO (25 ml). The reaction mixture was stirred at 0° C. for 3 hours, and then at room temperature for 1 hour, and then it was divided between water and ether. The aqueous layer was extracted with ether. The combined ether extracts were washed with 1M HCl, water, saturated NaHCO3, brine, and they were dried over Na2SO4 and evaporated in order to obtain crude (2S,3S)-2-methyl-3-tetrahydropyranyloxybutyraldehyde (6) (1.39 g, 100%) which was used directly for the next reaction without purification: 1H NMR (250 MHz, CDCl3) δ 9.78 (d, J=2.7 Hz, 0.5H); 9.74 (d, J=2.0 Hz, 0.5H); 4.76 to 4.62 (m, 1H); 4.15 to 3.73 (m, 2H); 3.53 to 3.43 (m, 1H); 2.62 to 2.46 (m, 1H); 1.82 to 1.51 (m, 6H); 1.29 (d, J=6.2 Hz, 1.5H); 1.18 (d, J=6.2 Hz, 1.5H); 1.11 (d, J=7.2 Hz, 1.5H); 1.07 (d, J=7.1 Hz, 1.5H); 13C NMR (62.5 MHz, CDCl3) δ 203.5; 203.1; 99.0; 95.1; 74.4; 71.0; 62.0; 51.6; 51.1; 30.5; 25.0; 19.2; 19.1; 18.6; 16.0; 9.7; 9.1; MS (CI) m/z 187. [M+H]+.

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