Isopropanol → 4,4,6-Trimethyl-1,2,3,4-tetrahydronaphthalen-1-one

Beteiligte Stoffe

Reaktionsschritte

A solution of chromium(VI)oxide (86 g, 0.861 mol) in acetic acid (400 mL) and water (40 mL) was added dropwise to a stirred solution of 1,1,7-trimethyl-1,2,3,4-tetrahydronaphthalene in acetic acid (70 mL) and the reaction mixture stirred 2.5 hours at room temperature. Isopropanol (5 mL) was added and the whole concentrated in vacuo. The residue was dissolved in hexane and filtered over celite. The organic was washed with water and brine, dried (Mg2SO4), filtered and evaporated to give 40.3 g of 1-oxo-4,4,6-trimethyl-1,2,3,4-tetrahydronaphthalene and used without further purification in the bromination (step e). 1H NMR (300 MHz; CDCl3): 1.36 (s, 6 H), 1.98 (t, J=6.9 Hz, 2 H), 2.38 (s, 3 H), 2.68 (t, J=6.9 Hz, 2 H), 7.01 (dd, J1=0.6 Hz, J2=7.9 Hz, 1 H), 7.19 (d, J=0.6 Hz, 1 H), 7.90 (d, J=8.1 Hz, 1 H).

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