反应详情

Treat a 0° C. mixture of 2-[4-(tert-butyl-diphenyl-silanyloxy)-piperidin-1-yl]-3-cyano-propionic acid methyl ester (3.32 g, 7.40 mmol) and cobalt (II) chloride hexahydrate (0.87 g, 3.65 mmol) in THF (60 mL) and water (30 mL) portion-wise with sodium borohydride (1.39 g, 36.7 mmol), warm to room temperature, and stir for 2 days under N2. Treat the reaction with 28% ammonium hydroxide (1 mL) and filter through hyflo. Remove the solvent from the filtrate in vacuo, dilute the residue with minimal water and brine, and extract three times with 3:1 chloroform:isopropanol. Dry the organic layer (Na2SO4), remove the solvent in vacuo to afford crude product, and purify with a 0 to 10% methanol in CH2Cl2 gradient to afford 1.68 g (54%) of the titled product. Rf=0.39 (9/1 CH2Cl2/methanol). ES MS (m/z): 423 (M+).

1. additionTreat a 0° C.
2. additionTreat
3. filtrationfilter through hyflo
4. customRemove the solvent from the filtrate in vacuo
5. additiondilute the residue with minimal water and brine
6. extractionextract three times with 3:1 chloroform
7. dry with materialDry the organic layer (Na2SO4)
8. customremove the solvent in vacuo
9. customto afford crude product
10. custompurify with a 0 to 10% methanol in CH2Cl2 gradient