HCID 12085276, compound → HCID 12085277, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 200 mg of tert-butyl naphthyl carbamate (Example 6) (0.59 mmol, 1 equiv.) in 1.6 mL anhydrous tert-butanol was added 200 mg of 3-tetrahydrofuroic aldehyde from above (excess) and 1.78 mL potassium tert-butoxide solution in tert-butanol (1.0 M, 1.78 mmol, 3 equiv.). The mixture was heated to 40° C. overnight, then cooled and quenched with NH4Cl saturated aqueous solution. The product was extracted with a dichloromethane/MeOH mixture (3×100 mL). The combined extracts were washed with brine, dried over MgSO4, and concentrated. 1H NMR analysis revealed that only 10% of the enone was consumed. The residue (300 mg) was dissolved in 4.0 mL dichloromethane and treated with 4 mL of a 1:1 mixture dichloromethane:TFA. The mixture was stirred for 1.5 h, then neutralized with saturated NaHCO3 aqueous solution, basified with 4 N NaOH solution and extracted with dichloromethane/MeOH (3×100 mL). The combined organic extracts were washed with brine, dried (MgSO4) and filtered and concentrated. The crude product was purified by column chromatography on silica gel using 10 to 50% EtOAc in hexane eluent mixtures to give the title compound (35 mg 0.11 mmol, 19% of theoretical yield).

Provenance & Evidence