Potassium Carbonate → 2-[3-(Tert-butyldimethylsilanyloxy)-2-(tert-butyldimethylsilanyloxymethyl)propoxy]-4-methoxy-5-thien-2-ylbenzaldehyde

Participants

Reaction Conditions

Reaction Steps

Ex-13D: To a solution of 2-hydroxy-4-methoxy-5-thien-2-ylbenzaldehyde (Ex-13C, 0.10 g, 0.43 mmol) in N,N-dimethylformamide (3 mL) was added potassium carbonate (0.18 g, 1.3 mmol) and the resulting yellow slurry was heated to 80° C. Methanesulfonic acid 3-(tert-butyldimethylsilanyloxy)-2-(tert-butyldimethylsilanyloxymethyl)propyl ester (Ex-13A, 0.24 g, 1.3 mmol) was then added dropwise in three equal portions with stirring at 1 h intervals. After the last addition, the reaction was stirred for an additional 1 h at 80° C. and cooled to room temperature. The mixture was diluted with water (15 mL) and extracted with ethyl acetate (3 x 15 mL). The combined organic phase was sequentially washed with a saturated ammonium chloride solution (15 mL), water (15 mL), and brine (15 mL), dried over sodium sulfate, and concentrated to a brown oil. Silica gel chromatography (ethyl acetate/hexanes, 1:6) gave 0.78 g (90%) of 2-[3-(tert-butyldimethylsilanyloxy)-2-(tert-butyldimethylsilanyloxymethyl)propoxy]-4-methoxy-5-thien-2-ylbenzaldehyde as a pale green solid, mp 91–92° C. 1H-NMR (300 MHz, CDCl3) δ 10.34 (s, 1H), 8.13 (s, 1H), 7.41 (dd, 1H, J=3.6, 1.2 Hz), 7.28 (dd, 1H, J=5.1, 1.2 Hz), 7.05 (dd, 1H, J=5.1, 3.6 Hz), 6.54 (s, 1H), 4.22 (d, 2H, J=5.7 Hz), 3.96 (s, 3H), 3.80 (d, 4H, J=5.7 Hz), 2.33 (pentet, 1H, J=5.7 Hz), 0.88 (s, 18H), 0.012 (s, 12H). HRMS (EI) Calcd. for C28H46O5SSi2: 550.2604 (M+); Found: 550.2593.

Provenance & Evidence