tert-Butyl acetate → rac-(1R*,8R*,9R*)-(9-hydroxy-tricyclo[6.2.2.02,7]dodeca-2,4,6-trien-9-yl)-acetic acid tert-butyl ester

HRID 1879348Notes

Reaction equation

HRID 1879348 reaction equation
C([Li])CCC.[C:6]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])(=[O:8])[CH3:7].[CH:14]12[CH2:26][CH2:25][CH:21]([C:22](=[O:24])[CH2:23]1)[C:20]1[C:15]2=[CH:16][CH:17]=[CH:18][CH:19]=1>C1COCC1.C1(C)C=CC=CC=1>[C:10]([O:9][C:6](=[O:8])[CH2:7][C:22]1([OH:24])[CH2:23][CH:14]2[CH2:26][CH2:25][CH:21]1[C:20]1[C:15]2=[CH:16][CH:17]=[CH:18][CH:19]=1)([CH3:13])([CH3:12])[CH3:11]

Participants

6

Reactant 3

HCID 10908tert-Butyl acetateHCID 5825961,4-Ethanonaphthalen-2(1H)-one, 3,4-dihydro-HCID 178418339Butyllithium

Product 1

HCID 70999528rac-(1R*,8R*,9R*)-(9-hydroxy-tricyclo[6.2.2.02,7]dodeca-2,4,6-trien-9-yl)-acetic acid tert-butyl ester

Reagents, catalysts & solvents 2

HCID 1140TolueneSolvent2×HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
-50 °C

Procedure

To a solution of 3.5 mL of DIPA in 6 mL THF were added dropwise 9.9 mL of n-butyllithium (2.5M in Hept) at −20° C. After 20 min, 12 mL of toluene were added and the solution was stirred for 30 min. The mixture was cooled to −50° C., 4.5 mL of tert.-butyl acetate were added and stirring was continued for 1 h at −50° C. Then, 2.5 g of rac-(1R*,8R*)-tricyclo[6.2.2.02,7]dodeca-2,4,6-trien-9-one dissolved in 6 mL of toluol were added and the solution was stirred at −50 to −20° C. over 2.5 h. The reaction mixture was poured on ice/aq. HCl, the organic phase was separated, washed with sat. aq. NaHCO3, dried over Na2SO4 and concentrated in vacuo. The crude reaction product was purified by CC with Hept/EtOAc (4:1) to yield 2.6 g of the major racemate, rac-(1R*,8R*,9R*)-(9-hydroxy-tricyclo[6.2.2.02,7]dodeca-2,4,6-trien-9-yl)-acetic acid tert-butyl ester as beige solid and 0.4 g of the minor racemate, rac-(1R*,8R*,9S*)-(9-hydroxy-tricyclo[6.2.2.02,7]dodeca-2,4,6-trien-9-yl)-acetic acid tert-butyl ester as yellow oil.

Workup

  1. stirringstirring
  2. waitwas continued for 1 h at −50° C
  3. additionwere added
  4. stirringthe solution was stirred at −50 to −20° C. over 2.5 h
  5. additionThe reaction mixture was poured on ice/aq
  6. customHCl, the organic phase was separated
  7. washwashed with sat. aq. NaHCO3
  8. dry with materialdried over Na2SO4
  9. concentrationconcentrated in vacuo
  10. customThe crude reaction product
  11. customwas purified by CC with Hept/EtOAc (4:1)

Sources & evidence

ORD record
ord-f56bf62e87d2453aaf7d19ff1b74c014
Source dataset
uspto-grants-2012_11
Patent number
US08314253B2

Reaction notes

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