- Preparation of enantiopure 2-acylazetidines and their reactions with chloroformates
-
Enantiopure 1-phenylethylazetidine-2-carboxylates and 2-acylazetidines were prepared and reacted with chloroformates to yield α-chloro-γ-amino butyric acid esters and ketones from ring opening reaction of azetidinium ion intermediate in a completely regio- and stereoselective manner.
- Ma, Sang-ho,Yoon, Doo Ha,Ha, Hyun-Joon,Lee, Won Koo
-
p. 269 - 271
(2007/10/03)
-
- ENANTIOSELECTIVE SYNTHESIS OF OPTICALLY PURE NATURAL S(+) OR UNNATURAL R(-) DABA
-
After optimization of the reaction conditions, optically pure S(+) DABA is obtained in more than 80percent overall yield.A modell is proposed to explain the dependence of asymmetric induction on the nature of the counter ion (Li(1+), Mg(2+), Bu4N(1+)).
- Solladie-Cavallo, A.,Simon, M. C.
-
p. 6011 - 6014
(2007/10/02)
-
- Application of N-Tritylmethionine in the Preparation of Heterocycles of Biological and Synthetic Interest
-
Treatment of the methylsulfonium salts of the corresponding N-tritylmethionine derivatives with sodium hydride or potassium tert-butoxide provides the heterocycles N-trityl-L-homoserine lactone (3), (S)- and (R)-3-(N-tritylamino)tetrahydrofuran (7a, 7b), (S)-1-hydroxy-3-(N-tritylamino)-2-pyrrolidinone (14), (S)-4-(N-tritylamino)-1,2-oxazinan-3-one (15), (S)-3-(N-tritylamino)-2-pyrrolidone (23), (S)-1-tert-butyloxycarbonylamino-3-(N-tritylamino)-2-pyrrolidone (27), and (S)-2-methyl-4-(N-tritylamino)-1,2-oxazinan-3-one (18).Methylation of 14 and 15 yields (S)-1-methoxy-3-(N-tritylamino)-2-pyrrolidone (17) and 18, respectively.The stereochemistry of compounds 3, 7a, and 17 has been determined by X-ray crystal structure analysis.
- Barlos, Kleomenis,Papaioannou, Dionysios,Voliotis, Stavros
-
p. 1127 - 1134
(2007/10/02)
-
