反应详情

Under argon, 2.00 g (6.64 mmol) of 2-methyl-propane-2-sulfinic acid 1-(8-ethyl-1,4-dioxa-spiro[4.5]dec-8-yl)-methylideneamide (prepared from 8-ethyl-1,4-dioxa-spiro[4.5]decane-8-carbonitrile using the protocol described for the synthesis of 19) were dissolved in 5 mL of absolute tetrahydrofuran. Then, 7.30 mL (7.30 mmol) of vinylmagnesium bromide (1M in tetrahydrofuran) were added dropwise at 0° C. and the reaction mixture was stirred for 17 h at room temperature. Another 16.6 mL (16.6 mmol) of vinylmagnesium bromide (1M in tetrahydrofuran) were added and the mixture stirred for 2 h at room temperature. The reaction mixture was cooled to 0° C. and 15 mL of saturated aqueous sodium sulphate solution were added. The suspension was filtered over celite, the organic layer was dried over magnesium sulphate, filtered, and concentrated in vacuo. The crude product was purified by flash chromatography (SiO2, 0%→100% ethyl acetate in heptane) to yield 1.30 g of the title compound 57 as mixture of diastereoisomers. Rt=2.19, 2.26 min (Method N). Detected mass: 330.2 (M+H+).

1. stirringthe mixture stirred for 2 h at room temperature
2. temperatureThe reaction mixture was cooled to 0° C.
3. filtrationThe suspension was filtered over celite
4. dry with materialthe organic layer was dried over magnesium sulphate
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe crude product was purified by flash chromatography (SiO2, 0%→100% ethyl acetate in heptane)