4-Methylbenzaldehyde → (R)-Phenyl(p-tolyl)methanol
Reaction equation
[C:1]1(B(O)O)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C([Zn]CC)C.CC1(C)[C@@H]2CC[C@@]1(CSSCC13C(C)(C)C(CC1)CC3N1CCOCC1)[C@H](N1CCOCC1)C2.[C:49]1([CH3:57])[CH:54]=[CH:53][C:52]([CH:55]=[O:56])=[CH:51][CH:50]=1>[Zn].C1(C)C=CC=CC=1>[C:1]1([C@H:55]([C:52]2[CH:53]=[CH:54][C:49]([CH3:57])=[CH:50][CH:51]=2)[OH:56])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1Participants
Conditions
- Temperature
- 60 °C
Procedure
To a toluene (4.0 mL) solution of phenylboronic acid (0.24 g, 2 mmol) was added diethylzinc (6.0 mL, 6 mmol 1.0 M in hexanes). The mixture was heated at 60° C. overnight and was then cooled to ambient temperature. The mixed zinc solution was transferred to another flask containing (1S,2R,4R)-1,2-bis((7,7-dimethyl-2-morpholinobicyclo[2.2.1]heptan-1-yl)methyl)disulfane (IIIa) (51 mg, 0.1 mmol) via syringe. After 10 minutes at ambient temperature, the mixture was cooled to 0° C. and neat p-tolualdehyde (108 μL, 1 mmol) was added dropwise. The reaction was stirred at 0° C. for 24 hours and was quenched by slow addition of sat. aq. NH4Cl (3 mL) and subsequent dilution with DCM (25 mL) and 1 N aq. HCl (30 mL). After layer separation, the aqueous solution was washed twice with DCM (20 mL). The DCM layers were combined, dried over Na2SO4, and concentrated to give a yellow oil which was purified by silica gel column chromatography (1:6 ethyl acetate:n-heptane) to give (R)-phenyl-p-tolyl-methanol as a white solid (0.147 g; 74% yield; 95.9% e.e.). The optical purity was determined by normal phase HPLC using a Chiralcel OD-H chiral column (eluted with isocratic 10:90 IPA/hexane, with 0.5 mL/minute flow rate; monitoring at 254 nm).
Workup
- temperaturewas then cooled to ambient temperature
- temperaturethe mixture was cooled to 0° C.
- customwas quenched by slow addition of sat. aq. NH4Cl (3 mL) and subsequent dilution with DCM (25 mL) and 1 N aq. HCl (30 mL)
- customAfter layer separation
- washthe aqueous solution was washed twice with DCM (20 mL)
- dry with materialdried over Na2SO4
- concentrationconcentrated
- customto give a yellow oil which
- customwas purified by silica gel column chromatography (1:6 ethyl acetate:n-heptane)
Sources & evidence
- ORD record
- ord-6d4d5446115c421f85f936ee2b22aee7
- Source dataset
- uspto-grants-2014_10
- Patent number
- US08859765B2
Reaction notes
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