Tetrahydrofuran → HCID 22399013, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 497 mg (1.16 mmol) of N-tertbutoxycarbonyl-O-(1-ethoxyethyl)-3,3-diphenylisoserine (3) in 20 mL of THF is added 261 mg (2.33 mmol) of solid potassium tert-butoxide and the mixture is stirred at 25° C. for 30 min. A solution of 134 mg (1.16 mmol) of methanesulfonyl chloride in 3.2 mL of THF is added and the mixture is stirred at 25° C. for 1.5 hour. The mixture is diluted with 80 mL of hexane and ethyl acetate, and this solution is extracted with 20 mL of saturated aqueous sodium bicarbonate solution and 10 mL of brine. The organic phase is dried over sodium sulfate and concentrated to give 243 mg (59%) of 2-tertbutoxy-4,4-diphenyl-5-(1-ethoxyethoxy)-4,5-dihydro-1,3-oxazin-6-one as a colorless oil. N-debenzoykl-N-tertbutoxycarbonyl-3'-phenyl taxol. To a small reaction vessel is added 90 mg (0.218 mmol) of 2-tertbutoxy-4,4-diphenyl-5-(1-ethoxyethoxy)-4,5-dihydro-1,3-oxazin-6-one, 40 mg (0.057 mmol) of 7-O-triethylsilyl baccatin III, 6.9 mg (0.057 mmol) of 4-dimethylamino pyridine (DMAP), and 0.029 mL of pyridine. The mixture is stirred at 25° C. for 12 hours and diluted with 100 mL of ethyl acetate. The ethyl acetate solution is extracted with 20 mL of 10% aqueous copper sulfate solution, dried over sodium sulfate and concentrated. The residue is filtered through a plug of silica gel eluted with ethyl acetate. Flash chromatography on silica gel eluted with ethyl acetate/hexane followed by recrystallization from ethyl acetate/hexane gives 44 mg (66%) of N-debenzoyl-N-tertbutoxycarbonyl-2 -(1-ethoxyethyl)3'-phenyl-7-O-triethylsilyl taxol as a ca 3:1 mixture of diastereomers

Provenance & Evidence