Allyl bromide → (+/-)-Dimethyl 2-allyl-1,2,3,4-tetrahydronaphthalene-2,6-dicarboxylate

Temperature

-70 °C

To a stirred solution of (±)-dimethyl 1,2,3,4-tetrahydronaphthalene-2,6-dicarboxylate from Step A (10.0 g, 40.4 mmol) in THF (200 mL) at −70° C. was added sodium bis(trimethylsilyl)amide (1.0 M in THF, 45 mL, 45 mmol) dropwise, over 10 min, such that the reaction temperature was maintained below −65° C. during the addition. The mixture was stirred at −70° C. for a further 40 min, then allyl bromide (5.87 g, 48.5 mmol) was added dropwise over 3 min. Stirring was continued at −70° C. for 2 h, then the mixture was partitioned between H2O (300 mL) and EtOAc (300 mL). The aqueous phase was extracted further with EtOAc (2×300 mL), and the combined organic extracts were washed with brine (100 mL), dried over Na2SO4, filtered, and concentrated in vacuo. The crude product was purified by silica gel chromatography, eluting with a gradient of hexane:EtOAc—100:0 to 0:100, to give the title compound. MS: m/z=289 (M+1).

1. temperaturesuch that the reaction temperature was maintained below −65° C. during the addition
2. stirringStirring
3. waitwas continued at −70° C. for 2 h
4. customthe mixture was partitioned between H2O (300 mL) and EtOAc (300 mL)
5. extractionThe aqueous phase was extracted further with EtOAc (2×300 mL)
6. washthe combined organic extracts were washed with brine (100 mL)
7. dry with materialdried over Na2SO4
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customThe crude product was purified by silica gel chromatography
11. washeluting with a gradient of hexane

ORD record

ord-3481fe6a2232422d8704f707b55fc324

Source dataset

uspto-grants-2008_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07390798B2