Boron Trichloride → (3S,7S)-3-(4-Hydroxy-phenyl)-1-methyl-2-oxo-6-((S)-1-phenyl-propyl)-2,3,5,6,7,8-hexahydro-1H-4-oxa-1,6-diaza-anthracene-7-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

(3S,7S)-3-[4-(3,4-Dichloro-benzyloxy)-phenyl]-1-methyl-2-oxo-6-((S)-1-phenyl-propyl)-2,3,5,6,7,8-hexahydro-1H-4-oxa-1,6-diaza-anthracene-7-carboxylic acid (1R,2S,5R)-2-isopropyl-5-methyl-cyclohexyl ester (0.80 g) was dissolved in 20 mL of dry DCM and cooled to 0° C. Boron trichloride (8 mL, 1M solution in hexanes) was added and the mixture stirred at 0° C. for 3.5 hours. The mixture was concentrated and treated with water/saturated sodium bicarbonate until pH 7. The aqueous mixture was extracted three times with ethyl acetate-THF (9-1) and organic layers combined. The combined organic layers were dried over sodium sulfate and concentrated to provide (3S,7S)-3-(4-Hydroxy-phenyl)-1-methyl-2-oxo-6-((S)-1-phenyl-propyl)-2,3,5,6,7,8-hexahydro-1H-4-oxa-1,6-diaza-anthracene-7-carboxylic acid (601 mg, LC/MS: m/z 474).

Provenance & Evidence