TY - JOUR
T1 - Chiral metal complexes. 28. A stereoselective synthesis of proline
AU - Birse, Ewan F.
AU - Williams, Peter A.
AU - Vagg, Robert S.
PY - 1988/8/1
Y1 - 1988/8/1
N2 - The complex Λ-β2-[Co(R,R-picchxn)(dehydropro)]2+, where R,R-picchxn is N,N′-di(2-picolyl)-1R, 2R-diaminocyclohexane and dehydropro is the anion of 1,2-dehydroproline may be synthesised quantitatively from Λ-β-[Co(R,R-picchxn)Cl2]+ and 5-amino-2-oxopentanoic acid in aqueous solution at room temperature. This ternary complex may in turn be reduced to Λ-β2-[Co(R,R-picchxn)(R,S-pro)]2+ (where pro is the anion of proline) in high yield by the use of aqueous sodium borohydride (also at room temperature) and the diastereoisomeric products separated quantitatively using chromatographic techniques. At 298.2 K the ratio of R-proline:S-proline produced is equal to 84:16 ± 2. Using the method, it is possible to stereoselectively synthesise 4- and 5- substituted diastereoisomers based on proline, in general.
AB - The complex Λ-β2-[Co(R,R-picchxn)(dehydropro)]2+, where R,R-picchxn is N,N′-di(2-picolyl)-1R, 2R-diaminocyclohexane and dehydropro is the anion of 1,2-dehydroproline may be synthesised quantitatively from Λ-β-[Co(R,R-picchxn)Cl2]+ and 5-amino-2-oxopentanoic acid in aqueous solution at room temperature. This ternary complex may in turn be reduced to Λ-β2-[Co(R,R-picchxn)(R,S-pro)]2+ (where pro is the anion of proline) in high yield by the use of aqueous sodium borohydride (also at room temperature) and the diastereoisomeric products separated quantitatively using chromatographic techniques. At 298.2 K the ratio of R-proline:S-proline produced is equal to 84:16 ± 2. Using the method, it is possible to stereoselectively synthesise 4- and 5- substituted diastereoisomers based on proline, in general.
UR - http://www.scopus.com/inward/record.url?scp=0038856840&partnerID=8YFLogxK
U2 - 10.1016/S0020-1693(00)86012-0
DO - 10.1016/S0020-1693(00)86012-0
M3 - Article
AN - SCOPUS:0038856840
SN - 0020-1693
VL - 148
SP - 57
EP - 61
JO - Inorganica Chimica Acta
JF - Inorganica Chimica Acta
IS - 1
ER -