Ethanol → (3R,4R,5S)-4-amino-5-azido-3-(1-ethyl-propoxy)-cyclohex-1-enecarboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of 300 mg of 26 and 1.25 mL EtOH in a 5.0 mL round-bottom flask equipped with a magnetic stirrer, a reflux condenser and an inert gas supply was added 0.31 mL of 96% sulfuric acid. The black solution was stirred for 18 h at RT and 8 h at 80° C. The black reaction mixture was cooled to RT treated with 8.0 μL of a mixture of 65 mL ammonium hydroxide 25% and 435 mL of brine, and extracted with 9.0 mL of EtOAc. The separated organic phase was washed with 10 mL of water and the water phase was back-extracted with 9.0 mL of EtOAc. The combined organic phases were dried (Na2SO4, 20 g), filtered and evaporated at 40° C./140-10 mbar to afford 175 mg crude product as a dark brown oil. The crude product was purified by SiO2 column chromatography eluting with EtOAc containing 1% v/v of 25% aqueous ammonium hydroxide. The combined fractions were evaporated at 40° C./140-10 mbar to afford 97 mg of 28 as a brown oil.

Provenance & Evidence