Acetone → (3aS,5S,6aR)-5-(tert-Butoxycarbonylamino)hexahydro-2H-cyclopenta[b]furan-3a-carboxylic acid

Participants

Reaction Steps

To an ice-cold solution of the product of Step H (426 g, 1.57 mol) and acetone (8.1 L) was added Jones reagent (710 mL) over 1 h 20 min. The resulting suspension was stirred at rt for 1 h, after which isopropyl alcohol (40 mL) was added, and the reaction stirred for 25 min at rt. Water was added, and the water/acetone was decanted off and evaporated. The insoluble material was dissolved separately in water and extracted with CH2Cl2. The green water/acetone concentrate was extracted with CH2Cl2 and the combined organic extracts were washed with brine, diluted with water and EtOAc and the organic layer was dried with Na2SO4. The organic layer was filtered, concentrated and the product was crystallized from MeCN, and the product of Step I was isolated by filtration as a white solid. 1H NMR (400 MHz, DMSO-d6) d=12.39-12.59 (m, 1H), 6.85-7.02 (m, 1H), 4.28 (d, J=5.4 Hz, 1H), 3.89-3.97 (m, 1H), 3.79-3.85 (m, 1H), 3.43-3.51 (m, 1H), 3.30-3.36 (m, 1H), 2.35-2.42 (m, 1H), 1.90 (d, J=11.0 Hz, 3H), 1.59-1.70 (m, 1H), 1.42-1.50 (m, 1H), 1.37 (s, 9H). Elemental anal calc for C13H21NO5: C, 57.55; H, 7.80; N, 5.16. Found: C, 57.34; H, 8.18; N, 5.08 mp: 147.4-149.1° C.

Provenance & Evidence