Water → (2R,3R)-3-(tert-Butyldimethylsilanyloxy)-2-methylpyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester-2-methyl ester

Temperature

-30 °C

To a solution of (2S,3R)-3-(tert-Butyldimethylsilanyloxy)pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester (51A) (195 mg, 0.54 mmol) in THF (6 mL) at −78° C. was added a 1.8 M solution of LDA (0.66 mL, 1.19 mmol). After stirring for 1.5 h at −78° C. and 0.5 h at −30° C., the reaction was cooled again to −78° C. and iodomethane (0.2 mL, 3.21 mmol) was added. The mixture was stirred at −78° C. for 1 h and at −20° C. for 4 h. After warming to rt, water and EtOAc were added and the layers were separated. The organic layer was washed with brine, dried (Na2SO4), filtered then concentrated under reduced pressure. The resulting residue was purified via preparative HPLC (Luna C-18, 21.1×100 mm, eluting with 75-100% solvent B (A=90% H2O—10% MeOH—0.1% TFA and B=10% H2O—90% MeOH—0.1% TFA) over 12 min; Flow rate at 20 mL/min. UV detection at 220 nm) to provide the title compound (36 mg). LC/MS m/z 374 [M+H]+.

1. temperaturethe reaction was cooled again to −78° C.
2. stirringThe mixture was stirred at −78° C. for 1 h and at −20° C. for 4 h
3. temperatureAfter warming to rt
4. customthe layers were separated
5. washThe organic layer was washed with brine
6. dry with materialdried (Na2SO4)
7. filtrationfiltered
8. concentrationthen concentrated under reduced pressure
9. customThe resulting residue was purified via preparative HPLC (Luna C-18, 21.1×100 mm
10. washeluting with 75-100% solvent B (A=90% H2O—10% MeOH—0.1% TFA and B=10% H2O—90% MeOH—0.1% TFA) over 12 min

ORD record

ord-702edb6a47a54377829dcc9e431977c0

Source dataset

uspto-grants-2008_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07405234B2