Benzyl Bromide → 2-Benzyl-3,4,8,8a-tetrahydro-8a-methyl-1,6(2H,7H)-naphthalenedione
Reaction equation
[CH3:1][C:2]12[C:11](=[O:12])[CH2:10][CH2:9][CH2:8][C:7]1=[CH:6][C:5](=[O:13])[CH2:4][CH2:3]2.C([N-]C(C)C)(C)C.[Li+].C(NC(C)C)(C)C.C([Li])CCC.[CH2:34](Br)[C:35]1[CH:40]=[CH:39][CH:38]=[CH:37][CH:36]=1>O1CCCC1.CCCCCC.O>[CH2:34]([CH:10]1[CH2:9][CH2:8][C:7]2[C:2]([CH3:1])([CH2:3][CH2:4][C:5](=[O:13])[CH:6]=2)[C:11]1=[O:12])[C:35]1[CH:40]=[CH:39][CH:38]=[CH:37][CH:36]=1Participants
Reactant 5
Product 1
Reagents, catalysts & solvents 3
Conditions
- Temperature
- 0 °C
Procedure
A solution of 3,4,8,8a-tetrahydro-8a-methyl-1,6(2H,7H)-naphthalenedione (2.5 g, 0.014 mole) in dry tetrahydrofuran (20 ml) was added to lithium diisopropylamide [made from dry diisopropylamine (1.95 ml 0.014 mole) and n-butyl-lithium (12.0 ml of a 1.15 M solution in hexane, 0.014 mole)] at -65° C. under nitrogen. The solution was allowed to warm to 0° C. and a solution of benzyl bromide (2.39 g, 0.014 mole) in dry tetrahydrofuran (6 ml) was added. This was stirred at room temperature overnight, poured into water and extracted with diethyl ether (100 ml). The organic phase was washed with 1 N hydrochloric acid (50 ml) and water (50 ml), then dried (Na2SO4) and evaported to give a dark oil. This was chromatographed on silica gel using diethyl ether/petroleum ether (1:1) as eluant giving the title compound which was further purified by distillation b.p. 190° C./0.01 mm. The product was isolated as a mixture of isomers.
Workup
- customat -65° C.
- extractionextracted with diethyl ether (100 ml)
- washThe organic phase was washed with 1 N hydrochloric acid (50 ml) and water (50 ml)
- dry with materialdried (Na2SO4)
- customto give a dark oil
- customThis was chromatographed on silica gel
Sources & evidence
- ORD record
- ord-01f06360e02742d2852d5d716ce17e98
- Source dataset
- uspto-grants-1983_05
- Patent number
- US04382094
Reaction notes
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