Sodium Hydroxide → 3-Hydroxy-hexahydro-pyrrolo[3,2-b]pyrrole-1,4-dicarboxylic acid 4-benzyl ester 1-tert-butyl ester

The crude ester (42, 11.7 g crude, ˜11.0 mmol) was dissolved in 1:1 THF/MeOH (75 mL) and cooled to 0° C. and 1M NaOH (45 mL) was added in one portion. After 45 min, the reaction mixture was quenched with glacial HOAc (10 mL) and concentrated in vacuo. The residue was dissolved in EtOAc and the organic solution was washed successively with aqueous NaHCO3 (5×) and brine, dried over anhydrous Na2SO4, filtered, and concentrated. The crude product was absorbed onto silica gel and purified by flash silica gel chromatography (2:1 to 1:2 hexanes/EtOAc) to provide 43 as a white foam (3.5 g, 88%, 2 steps): 1H NMR (300 MHz, CDCl3): δ7.39 (m, 5H), 5.15 (m, 2H), 4.40 (m, 2H), 4.13 (m, 1H), 3.54 (m, 3H), 3.35 (m, 1H), 2.83 (m, 1H), 2.11 (m, 2H), 1.49 (s, 9H) ppm. Mass spectrum, m/z [306.6] (M−t-Bu)+.

1. customthe reaction mixture was quenched with glacial HOAc (10 mL)
2. concentrationconcentrated in vacuo
3. dissolutionThe residue was dissolved in EtOAc
4. washthe organic solution was washed successively with aqueous NaHCO3 (5×) and brine
5. dry with materialdried over anhydrous Na2SO4
6. filtrationfiltered
7. concentrationconcentrated
8. customThe crude product was absorbed onto silica gel
9. custompurified by flash silica gel chromatography (2:1 to 1:2 hexanes/EtOAc)

ORD-Eintrag

ord-56df0870535d48d1b2a86c166dacc525

Quelldatensatz

uspto-grants-2013_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08415486B2