Methoxymethyl-triphenylphosphonium chloride → 4-(2,5-Dibromo-4-hydroxy-3-methoxyphenyl)-3,3-dimethylbutanal

Lithium bis(trimethylsilyl)amide solution (20 ml, 20 mmol, 1M in THF) was added to a mixture methoxy methyl triphenyl phosphonium chloride (6.9 g, 20 mmol) in 25 ml THF dropwise at 0° C. and stirred for 15 min and it was added to a mixture of the product of STEP 3 (2.6 g, 7.1 mmol ) in 15 ml THF dropwise at 0° C. After 5 min, the reaction was quenched with H2O. The product was extracted with ethyl acetate. The aqueous layer was extracted with ethyl acetate. The combined organic layer was washed with H2O, brine, dried with Na0.2SO4, and concentrated. The residue was purified by chromatography (on silica gel, ethyl acetate/hexane=1/3) to give a brown oil in 1.14 g. It was dissolved in 20 ml THF and 20 ml 2N HCl. The reaction was stirred at room temperature for 30 min. THF was evaporated. The product was extracted with ethyl acetate and washed H2O. The aqueous layer was extracted with ethyl acetate. The combined organic layer was washed with brine, dried with Na2SO4, and concentrated. The residue was purified by chromatography (on silica gel, ethyl acetate/hexane=1/3) to yield a viscous oil in 0.783 g. NMR spectra of the product were consistent for the proposed structure.

1. waitAfter 5 min
2. customthe reaction was quenched with H2O
3. extractionThe product was extracted with ethyl acetate
4. extractionThe aqueous layer was extracted with ethyl acetate
5. washThe combined organic layer was washed with H2O, brine
6. customdried with Na0.2SO4
7. concentrationconcentrated
8. customThe residue was purified by chromatography (on silica gel, ethyl acetate/hexane=1/3)
9. customto give a brown oil in 1.14 g
10. stirringThe reaction was stirred at room temperature for 30 min
11. customTHF was evaporated
12. extractionThe product was extracted with ethyl acetate
13. washwashed H2O
14. extractionThe aqueous layer was extracted with ethyl acetate
15. washThe combined organic layer was washed with brine
16. dry with materialdried with Na2SO4
17. concentrationconcentrated
18. customThe residue was purified by chromatography (on silica gel, ethyl acetate/hexane=1/3)
19. customto yield a viscous oil in 0.783 g

ORD record

ord-93fafea441424428b75c67fd1217f11a

Source dataset

uspto-grants-2003_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06531494B1