Trifluoroacetic acid → (3R,10S)-2-methyl-5-methyl-3-(9-oxo-1,8-diazatricyclo[10.6.1.013,18]nonadeca-12(19),13(18),14,16-tetraen-10-ylcarbamoyl)hexanoic acid

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Reaction Steps

Alternatively, the less polar stereoisomer of (3R,10S)-2-methyl-5-methyl-3-(9-oxo-1,8-diazatricyclo- [10.6.1.013,18 ]nonadeca-12(19),13(18),14,16-tetraen-10-ylcarbamoyl)hexanoic acid t-butyl ester prepared in Example 5D above (15 mg) was taken up in CH2Cl2 (2.4 mL) and TFA (0.6 mL) and the resulting mixture was stirred at room temperature for 4 hrs. The solvent was removed under reduced pressure at 35° C. Then ethyl acetate was added and the solution was washed with water (3×10 mL). The organic layer was dried over Na2SO4, filtered and evaporated to dryness. Recrystallization from ethyl acetate/petroleum ether gave (3R,10S)-2-methyl-5-methyl-3-(9-oxo-1,8-diazatricyclo[10.6.1.013,18 ]nonadeca-12(19),13(18),14,16-tetraen-10-ylcarbamoyl)hexanoic acid as a white solid (7 mg), MS: 456.3 (M+H)+.

Provenance & Evidence