2-Chloroethyl methyl ether → (RS,SR)-2-benzenesulfonyl-2-(6-chloro-9-methoxymethyl-2,3,4,9-tetrahydro-1H-carbazol-2yl)-propionic acid methyl ester

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Reaction Steps

350 mg (0.81 mmol) of (RS,SR)-2-benzenesulfonyl-2-(6-chloro-2,3,4,9-tetrahydro-1H-carbazol-2-yl)-propionic acid methyl ester (from example 3) in 10 mL of THF at 0° C., were treated with 39 mg (0.89 mmol, 1.1 eq) of NaH (55% in oil) portionwise within 30 min. 0.10 mL (1.22 mmol, 1.5 eq) of 1-chloro-2-methoxy-ethane was added and the ice bath removed. After 2 hours, the reaction was quenched by addition of aqueous NH4Cl sat., extracted with EtOAc and the organic phases dried over Na2SO4. Evaporation of the solvent afforded (RS,SR)-2-benzenesulfonyl-2-(6-chloro-9-methoxymethyl-2,3,4,9-tetrahydro-1H-carbazol-2yl)-propionic acid methyl ester as yellow solid, MS: 493 (MNH4′). The crude material was used in the next step without further purification.

Provenance & Evidence