- Use of (S)-5-(2-methylpyrrolidin-2-yl)-1H-tetrazole as a novel and enantioselective organocatalyst for the aldol reaction
-
The novel organocatalyst (S)-5-(2-methylpyrrolidin-2-yl)-1H-tetrazole (4) catalyzes the aldol reaction between acetone and various aldehydes with superior enantioselectivity to the existing organocatalysts (S)-proline (1) and (S)-5-(Pyrrolidin-2-yl)-1H-tetrazole (3). Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Tong, Sok-Teng,Harris, Paul W. R.,Barker, David,Brimble, Margaret A.
-
p. 164 - 170
(2008/09/18)
-
- Preparation and Use of Chloromethyl (-)-Menthyl Ether in the Synthesis of Optically Pure α-Branched α-Amino Nitriles
-
The synthesis of optically pure chloromethyl (-)-menthyl ether (2b) and its use in the synthesis of di-(-)-menthyl acetal (-)-menthyl (+)-menthyl acetals are described.The diastereomeric mixed acetals 7a,b and 8a,b are easily obtainable from the nitrones 5 and 6, KCN and 2b.The mixture of diastereomers are separated into the pure components 7a, 7b and 8a, 8b by simple silica gel column chromatography.Hydrolysis of these products (H2O2/Na2CO3, ultrasound) followed by N-O cleavage affords the heterocyclic α-methyl-α-amino amides 11a, 11b and 12a, 12b.These are subsequently hydrolyzed to give the corresponding α-methyl-α-amino acids with S and R configuration, respectively.
- Shatzmiller, Shimon,Dolithzky, Ben-Zion,Bahar, Eliezer
-
p. 375 - 379
(2007/10/02)
-