反应详情

温度

-78 °C

In a 500 ml round-bottomed flask methyl (2Z,5S)-6-{[(1,1-dimethylethyl)(diphenyl)silyl]oxy}-5-({[(phenylmethyl)oxy]carbonyl}amino)-2-hexenoate D5 (3.58 g) was dissolved in dry DCM (122 ml) and the solution cooled at −78° C. To this solution DIBAL-H 1 M in THF (33.7 ml, 33.7 mmol) was added dropwise and the mixture left under stirring at −78° C. for 5 hours. After this time a saturated NH4Cl aqueous solution (250 ml) was added and the reaction mixture filtered through a celite pad the solid was washed with DCM (5×200 ml) and the resulting filtrate transferred into a separatory funnel. The phases were separated and the aqueous one back extracted with DCM (3×100 mls). The collected organic phases were dried (Na2SO4) and solvent removed under reduced pressure to give an oil. This crude was purified by column chromatography on silica gel (SP4 SNAP 340 g, Cy/EtOAc from 100/0 to 80/20). Collected fractions gave the title compound D6 (3.3 g) as colorless thick oil. HPLC (walk-up): rt=7.30 min. C30H37NO4Si requires 503. 1H NMR (400 MHz, CDCl3-d6) δ (ppm): 7.74-7.30 (m, 15 H), 5.71 (m, 1 H), 5.52 (m, 1 H), 5.80-5.61 (m, 1 H), 561-3.36 (m, 1 H), 5.20-4.94 (m, 2 H), 4.25-3.98 (m, 2 H), 3.91-372 (m, 1 H), 3.72-3.58 (m, 2 H), 2.50-2.26 (m, 2 H), 1.07 (s, 9 H)

1. waitthe mixture left
2. filtrationthe reaction mixture filtered through a celite pad the solid
3. washwas washed with DCM (5×200 ml)
4. customthe resulting filtrate transferred into a separatory funnel
5. customThe phases were separated
6. extractionthe aqueous one back extracted with DCM (3×100 mls)
7. dry with materialThe collected organic phases were dried (Na2SO4) and solvent
8. customremoved under reduced pressure
9. customto give an oil
10. customThis crude was purified by column chromatography on silica gel (SP4 SNAP 340 g, Cy/EtOAc from 100/0 to 80/20)