Water → HCID 22749578, compound

Participants

Reaction Steps

3.3 g (0.019 mole) of benzyl bromide are added all at once to a solution of 4.62 g (0.01 mole) of the alpha isomer of tert-butyl 4-carboxy-alphaphthalimido-8-oxa-1-thia-3-azaspiro[4.5]decane-2-acetate in 50 ml of dimethylformamide, and then, over a period of 20 minutes, 1.32 g (0.013 mole) of triethylamine in 5 ml of dimethylformamide are added. The reaction mixture is gently stirred overnight at ambient temperature. The clear solution thus obtained is poured into a mixture of ice and water and then extracted with benzene. After washing the organic phase with a 5% aqueous solution of sodium hydrogen carbonate and then with water, it is evaporated to dryness. The residue obtained is recrystallized from diethyl ether to give 4.7 g (0.00085 mole) of tert-butyl 4-benzyloxycarbonyl-alpha-phthalimido-8-oxa-1-thia-3-azaspiro[4.5]decane-2-acetate (yield: 85.2% of theory); M.P. 168-169° C. Another synthesis with quantities 10 times larger gave a yield of 93.6% of theory.

Provenance & Evidence