Reaktion #6520

Reaktionsgleichung

17

(2R,5S)-1-[2-(Butyldiphenylsiloxymethyl)-1,3-oxathiolan-5-yl]cytosine

tetrabutylammonium fluoride

→

3

Ausbeute 75.0%

(2R,5S)-1-[2-(Hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine

Ausbeute 75.0%

Lösungsmittel

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigethe disappearance of starting material (30 min)
2. 2
   EinengenThe reaction mixture was concentrated under reduced pressure
3. 3
   Sonstigethe residue purified by preparative TLC

Vorschrift

To a solution of the β anomer 17 (0.15 g, 0.32 mmol) in THF (25 mL) was added tetrabutylammonium fluoride 1M in THF (0.35 mL, 0.35 mmol, 1.1 eq) and the reaction was allowed to stir at room temperature until TLC indicated the disappearance of starting material (30 min). The reaction mixture was concentrated under reduced pressure and the residue purified by preparative TLC using 12% MeOH/CHCl3 as development solvent to give 0.055 g (75%) of 3 from ethyl ether/MeOH (trace) as a white crystalline solid. [α]23D =-121.6 (c 1.1, MeOH) (for the S,R isomer 2 [α]23D =120.96 (c 1.06, MeOH)); 1H NMR: ((CD3)2SO) δ 3.03 (dd, J5,4a =4.4 Hz, J4a,4b =11.86 Hz, 1 H, 4a-H), 3.43 (dd, J5,4b =5.3 Hz, J4a,4b =11.86 Hz, 1 H, 4b-H), 3.80 (app t on D2O exchange goes to d, J2,2-CH2-OR =4.17 Hz, 2 H, 2-CH2 -OH), 5.27 (t, J2-CH2,OH =4.6 Hz, 1 H, 2-CH2OH), 5.22 (t, J2,2-CH2-OH =4.17 Hz, 1 H, 2-H), 5.88 (d, J5,6 =7.47 Hz, 1 H, H-5), 6.21 (app t, J=5.05 and 4.84 Hz, 1 H, 5-H), 7.19 (bs, 2 H, NH2), 7.89 (d, J5,6 =7.47 Hz, 1 H, H-6).

Quelle