Trifluoroacetic acid → (5S,12S)-12-[(R)-[(3R,4R,5R)-4-{[tert-butyl(dimethyl)silyl]oxy}-3-hydroxy-5-(3-(4-methoxybenzyl)-2,4-dioxo-3,4-dihydro-1(2H)-pyrimidinyl)tetrahydro-2-furanyl](hydroxy)methyl]-5-[(1S)-1-hydroxyethyl]-3,6-dioxo-1-phenyl-2-oxa-4,7,11-triazatridecan-13-oic acid

Participants

Reaction Conditions

Reaction Steps

A solution of trifluoroacetic acid (0.3 drops) in methylene chloride (1 ml) was cooled to 0° C. tert-butyl (5S,12S)-12-[(R)-[(3R,4R,5R)-3,4-bis{[tert-butyl(dimethyl)silyl]oxy}-5-(3-(4-methoxybenzyl)-2,4-dioxo-3,4-dihydro-1(2H)-pyrimidinyl)tetrahydro-2-furanyl](hydroxy)methyl]-5-[(1S)-1-hydroxyethyl]-3,6-dioxo-1-phenyl-2-oxa-4,7,11-triazatridecan-13-oate (20 mg, 0.02 mmol, obtained from Example 10) was added and the resulting mixture was stirred at 0° C. for 20 minutes. Additional trifluoroacetic acid (0.9 ml) was gradually added over 1 hour after which the mixture was warmed to room temperature and stirred for 2 hours. The volatiles were removed in vacuo. The residue was azeotroped with toluene, and was then dissolved in methylene chloride (0.5 ml). Cold trifluoroacetic acid (0.5 ml) and the mixture was stirred for 3 hours. The volatiles were removed in vacuo and the residue was azeotroped with toluene to provide (5S,12S)-12-[(R)-[(3R,4R,5R)-4-{[tert-butyl(dimethyl)silyl]oxy}-3-hydroxy-5-(3-(4-methoxybenzyl)-2,4-dioxo-3,4-dihydro-1(2H)-pyrimidinyl)tetrahydro-2-furanyl](hydroxy)methyl]-5-[(1S)-1-hydroxyethyl]-3,6-dioxo-1-phenyl-2-oxa-4,7,11-triazatridecan-13-oic acid (16 mg, 95%) as a yellow solid.

Provenance & Evidence