反应详情

温度

-78 °C

n-Butyllithium (2.5M in hexane, 10 mmol) was added to a solution of the compound from step 29c (2.70 g, 8.88 mmol) in 40 mL of THF cooled to -78° C. The resulting yellow solution was stirred for 30 min at -78° C., and a solution of 1,2-dihydro-6,7-dimethoxy-3-nitronaphthalene (2.227 g, 9.48 mmol), from Example 1b, precooled to -78° C., was added via cannula. The reaction was stirred for 2 hours at -78° C., then the reaction was quenched by the addition of 10 mL of satd. NH4Cl. After warming to room temperature, the organic layer was separated, and the aqueous layer was extracted with 2×50 mL of methylene chloride. The organics were combined, dried over MgSO4 and concentrated. The crude product was dissolved in 45 mL of methanol and treated with 8 mL of triethylamine. This solution was stirred for 15 hours at room temperature. The solvent was removed under reduced pressure, and the residue was chromatographed on silica gel, eluting with 30-60% ethyl acetate in hexane, to afford after removal of the solvent and drying, 3.64 g (89% yield) of the title product as an oil. MS: 461 (M+H)+. NMR showed a mixture of diastereomers.

1. customprecooled to -78° C.
2. additionwas added via cannula
3. stirringThe reaction was stirred for 2 hours at -78° C.
4. customthe reaction was quenched by the addition of 10 mL of satd
5. temperatureAfter warming to room temperature
6. customthe organic layer was separated
7. extractionthe aqueous layer was extracted with 2×50 mL of methylene chloride
8. dry with materialdried over MgSO4
9. concentrationconcentrated
10. dissolutionThe crude product was dissolved in 45 mL of methanol
11. additiontreated with 8 mL of triethylamine
12. stirringThis solution was stirred for 15 hours at room temperature
13. customThe solvent was removed under reduced pressure
14. customthe residue was chromatographed on silica gel
15. washeluting with 30-60% ethyl acetate in hexane
16. customto afford
17. customafter removal of the solvent
18. customdrying