N-cyclohexylidene-2-methylpropane-2-sulfinamide

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

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

Procedure: n-Butyllithium (1.3 eq, 8.07 mL of a 1.6M soln in hexanes) was added dropwise to a cooled (−78° C.) solution of N,N-dimethyl methanesulfonamide (1.35 eq, 1.65 g) in 100 mL of dry THF under anhydrous atmosphere. The mixture was stirred for 30 min at that temperature and then transferred via cannula to a solution of sulfinyl imine 1200-B (2.0 g) in 100 mL of dry THF at −78° C. After addition was completed, the reaction mixture was stirred for 1 h. The reaction was quenched at −78° C. by addition of 20 mL of aqueous saturated ammonium chloride solution. The mixture was allowed to reach room temp and then partitioned between dichloromethane (300 mL) and aqueous saturated sodium bicarbonate solution (300 mL). The aqueous layer was back extracted with dichloromethane (2×200 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The residue was chromatographed on silica gel (gradient:dichloromethane/hexanes; 1:1 to 30% acetone in dichloromethane/hexanes; 1:1) to afford the product 1200-C (1.36 g; 42%) as a colorless oil. After addition the reaction mixture was stirred for 1 h The reaction was quenched at −78° C. by addition of 20 mL of aqueous saturated ammonium chloride solution to reach room temp partitioned between dichloromethane (300 mL) and aqueous saturated sodium bicarbonate solution (300 mL) The aqueous layer was back extracted with dichloromethane (2×200 mL) The combined organic layers were dried over magnesium sulfate filtered concentrated The residue was chromatographed on silica gel (gradient:dichloromethane/hexanes; 1:1 to 30% acetone in dichloromethane/hexanes; 1:1)

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Titanium tetraethoxide (2 eq, 3.56 mL, d 1.088) was added to a solution of cyclohexanone (1.2 eq, 1.0 g, 1.05 mL, d 0.947) in 20 mL of dry THF under nitrogen atmosphere. After 5 min, (S)-t-butanesulfinamide (1200-A, 1.028 g) in 10 mL of THF was added dropwise. The mixture was heated to 60° C. overnight. The reaction mixture was poured into an equal volume of aqueous saturated sodium bicarbonate solution with rapid stirring and immediately filtered through celite. The filter cake was washed with ethyl acetate (50 mL). The layers in the filtrate were separated and the aqueous layer was extracted with ethyl acetate (30 mL). The combined organic layers were dried over magnesium sulfate, filtered and concentrated. The residue was chromatographed on silica gel (gradient:ether/hexanes; 1:9 to 1.1) to afford the product 1200-B (1.3 g; 76%) as a colorless oil. The product was kept under inert atmosphere at −20° C. immediately filtered through celite The filter cake was washed with ethyl acetate (50 mL) The layers in the filtrate were separated the aqueous layer was extracted with ethyl acetate (30 mL) The combined organic layers were dried over magnesium sulfate filtered concentrated The residue was chromatographed on silica gel (gradient:ether/hexanes; 1:9 to 1.1)