Diisobutylaluminum hydride → (2S)-1-tert-Butyl 2-ethyl 5-hydroxypyrrolidine-1,2-dicarboxylate

A solution of 10.0 g of 167 (38.9 mmol) in 100 ml of anhydrous THF was cooled to −78° C. and added very slow with 85.5 ml of DIBAL-H (85.5 mmol, 2.2 eq., 1 M/THF). After one hour, the reaction was terminated by adding 10 ml of isopropanol at low temperature, followed by addition of 240 ml of a K—Na tartrate solution (1.77 M), and the mixture was slowly thawed, initially to 0° C. and subsequently to RT. The resulting phases were separated, the organic phase was extracted with 3×200 ml of MTBE, and the combined organic phases were washed with 100 ml of saturated NaCl solution. After drying over MgSO4, the solvent was removed to obtain 9.69 g of 205 (37.4 mmol, 96%) as a yellowish oily residue which was further reacted without purification. For analytical purposes, a small sample was purified using silica gel column chromatography (EE/CH 1:1).

1. customthe reaction was terminated
2. additionby adding 10 ml of isopropanol at low temperature
3. additionfollowed by addition of 240 ml of a K—Na tartrate solution (1.77 M)
4. customwas slowly thawed, initially to 0° C. and subsequently to RT
5. customThe resulting phases were separated
6. extractionthe organic phase was extracted with 3×200 ml of MTBE
7. washthe combined organic phases were washed with 100 ml of saturated NaCl solution
8. dry with materialAfter drying over MgSO4
9. customthe solvent was removed

ORD record

ord-1b2d9b0142674adc953688c0c61d5d87

Source dataset

uspto-grants-2012_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08242105B2