反应详情

温度

-10 °C

To a solution of (methylsulfinyl)(methylthio)methane (27.70 g, 223.0 mmol) in tetrahydrofuran (90 mL) at −10° C. was added dropwise, a solution of 2.5 M n-butyllithium in hexane (89.2 mL, 223 mmol). The mixture was stirred at −10° C. for 2 hours. It was then cooled to −78° C. and transferred by cannula in a slow manner to a solution of [2-bromo-1-(bromomethyl)ethoxy](tert-butyl)diphenylsilane (42 g, 93 mmol, from Step 1) in tetrahydrofuran (70 mL, 900 mmol) held at −78° C. The mixture was stirred with warming to room temperature over 2 nights. Water was added, and then the product was extracted with three portions of DCM. The combined extracts were dried over sodium sulfate, filtered and concentrated. Flash chromatography (eluting with a gradient from 0-100% ethyl acetate/hexanes) afforded desired product as a mixture of diastereomers (34.1 g, 88%). 1H NMR (300 MHz, CDCl3), diastereomers: δ 7.74-7.58 (m, 8H), 7.48-7.31 (m, 10H), 4.52 (tt, 1H), 4.42 (tt, 1H), 3.05-1.99 (m, 8H), 2.47 (s, 3H), 2.42 (s, 3H), 2.13 (s, 3H), 2.00 (s, 3H), 1.05 (s, 9H), 1.02 (s, 9H).

1. temperatureIt was then cooled to −78° C.
2. customheld at −78° C
3. stirringThe mixture was stirred
4. temperaturewith warming to room temperature over 2 nights
5. extractionthe product was extracted with three portions of DCM
6. dry with materialThe combined extracts were dried over sodium sulfate
7. filtrationfiltered
8. concentrationconcentrated
9. washFlash chromatography (eluting with a gradient from 0-100% ethyl acetate/hexanes)