Sulfuric Acid → (3R,4S,5R)-4-amino-3-(1-ethyl-propoxy)-5-methanesulfonyloxy-cyclohex-1-enecarboxylic acid ethyl ester

Participants

Reaction Steps

To a solution of 120 mg of 18 and 500 μl EtOH in a 5 mL round-bottom flask equipped with a magnetic stirrer, a reflux condenser and an inert gas supply was added 120 μl sulphuric acid (96%). The reaction mixture was refluxed for 16 h, cooled to RT and diluted with 1.0 mL of EtOAc then cooled to 0-5° C. The cooled solution was treated with 100 μl of a 28% aqueous NaOH solution and with 257 μl of a 25% aqueous NH4OH. The well stirred mixture was diluted with 1.5 mL of water, extracted and the organic phase was separated, dried (Na2SO4), filtered and evaporated at 20° C./120-10 mbar and dried for 1 h at 20° C./<10 mbar to afford 56 mg of 20 as colorless oil.

Provenance & Evidence