Reaktion #1906050

Reaktionsgleichung

tert-butyl 5-biphenyl-4-yl-2-(2-{[tert-butyl(dimethyl)silyl]oxy}ethyl)-3-hydroxypentanoate

4-methoxybenzyl 2,2,2-trichloroethanimidoate

→

title compound

Ausbeute 34.4%

1,1-Dimethylethyl 5-(4-biphenylyl)-2-(2-{[(1,1-dimethylethyl) (dimethyl)silyl]oxy}ethyl)-3-({[4-(methyloxy)phenyl]methyl}oxy)pentanoate

Ausbeute 34.4%

Lösungsmittel

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued at room temperature for a further 2 h
3. 3
   workup.STIRRINGby stirring at room temperature for 2 h
4. 4
   Sonstigewere carried out before evaporation of the solvent
5. 5
   SonstigeThe residue was chromatographed on silica gel (5% to 10% diethyl ether: cyclohexane)

Vorschrift

Boron trifluoride etherate (8.0 μL, 65 μmol) was added to a stirred solution of tert-butyl 5-biphenyl-4-yl-2-(2-{[tert-butyl(dimethyl)silyl]oxy}ethyl)-3-hydroxypentanoate (7.88 g, 16.3 mmol) and 4-methoxybenzyl 2,2,2-trichloroethanimidoate (6.88 g, 24.5 mmol) in tetrahydrofuran (40 mL) at 0° C. under nitrogen. The reaction was allowed to warm to room temperature at which stirring was continued for 2 h. A further portion of boron trifluoride etherate (8.0 μL, 65 μmol) was then added and stirring was continued at room temperature for a further 2 h. Two further additions of boron trifluoride etherate (8.0 μL, 65 μmol) followed by stirring at room temperature for 2 h were carried out before evaporation of the solvent. The residue was chromatographed on silica gel (5% to 10% diethyl ether: cyclohexane) to give the title compound (3.39 g, 34%) as a pale yellow oil which was a mixture of diastereomers. LC/MS: 4.81 min; z/e 605, calcd (M+1) 605. 1H NMR (400 MHz: CDCl3): 7.55 (2H), 7.45 (4H), 7.35-6.80 (7H), 4.50 (2H), 3.80 (3H), 3.60 (3H), 2.95 (1H), 2.80 (1H), 2.65 (1H), 1.85 (4H), 1.45 (9H), 0.85 (9H), 0.5 (6H).

Quelle