N-tert-butyl-2,2,2-trichloroacetamide

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: (S)-1-(tert-Butoxy)-3-cyclohexyl-propan-2-ol was prepared according to the procedure described by Alan Armstrong et al., Tetrahedron Letters 1988, 29: 2483-2486. Three drops of boron trifuoride etherate were added to a solution of (S)-3-cylcolhexyl 1,2-propanediol (540 mg, 3.4 mmol) and tert-butyl 2,2,2-trichloroacetamide (670 μL, 3.8 mmol) in cyclohexane (7 mL) at ambient temperature. After stirring for 21 hours, a saturated solution of NaHCO3 was added to the reaction mixture and the mixture was extracted with EtOAc (2×). The EtOAc phases were combined, dried (MgSO4) and concentrated. The residue was chromatographed (silica gel; EtOAc/hexanes, 1:10) to afford a clear oil (235 mg, 32%). 1H NMR (CDCl3, 300 MHz) δ0.79-1.01 (m, 2H), 1.12-1.53 (m, 6H), 1.20 (s, 9H) 1.58-1.84 (m, 5H), 3.12 (dd, J=9, 9 Hz, 1H), 3.35 (dd, J=3, 9 Hz, 1H), 3.81 (m, 1H); MS (CI/NH3) m/z: (M+H)+ 215. the mixture was extracted with EtOAc (2×) dried (MgSO4) concentrated The residue was chromatographed (silica gel; EtOAc/hexanes, 1:10)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Benzyl alcohol derivatives E6 dissolved in dichloromethane or chloroform are treated with isobutylene in phosphoric acid-boron trifluoride etherate for about 1 to 3 hours at about -78° C. to -60° C. then 18 hours at room temperature or with tert-butyl-2,2,2-trichloroacetamidate in the presence of a catalytic amount of boron trifluoride etherate in cyclohexane or in a mixture of cyclohexane-dichloromethane at room temperature for about 18-24 hours to produce tert-butyl ether derivatives E7.

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 3-bromo-phenyl-acetic acid (10 gm, 46.5 mmol) and methylene chloride (47 mL) was added a solution of t-butyl-2,2,2-trichloroacetamidate (20.3 g, 93.0 mmol) and cyclohexane (186 mL) followed by borontrifluoride etherate (0.93 mL, 7.3 mmol). After stirring overnight, solid sodium bicarbonate was added and the reaction then filtered through a pad of silica gel utilizing methylene chloride as solvent. Concentration gave 9.11 g (72%) of a colorless oil. the reaction then filtered through a pad of silica gel Concentration