Functionalization of olefins by alkoximidoylnitrenes
作者:A. Subbaraj、O. Subba Rao、Walter Lwowski
DOI:10.1021/jo00277a037
日期:1989.8
Stereoselectivity in the amination of chiral cyclohex-3-en-1-one ketals
作者:Stefania Fioravanti、Giuseppe Luna、Lucio Pellacani、Paolo A. Tardella
DOI:10.1016/s0040-4020(97)00161-0
日期:1997.3
Optically active cyclohex-3-en-1-one ketals by photolysis of N(3)CO(2)Et or N3C(OEt)NMs or by CaO induced alpha-elimination of NsONHCO(2)Et give diastereomeric aziridines (up to 72% yields, up to 60% d.e.). A simple HPLC separation allows to obtain practically pure aziridines. The conversion of the main product to the ketal of (R)-N-(ethoxycarbonyl)-beta-aminocyclohexanone is also reported and a further oxidation directly gives a derivative of(R)-2-aminoadipic acid. (C) 1997 Elsevier Science Ltd.
Stereoselective azide cycloaddition to chiral cyclopentanone enamines
作者:Stefania Fioravanti、Lucio Pellacani、Damiano Ricci、Paolo A Tardella
DOI:10.1016/s0957-4166(97)00239-5
日期:1997.7
The enamine derived from cyclopentanone and (2R,5R)-2,5-bis(methoxymethyl)pyrrolidine added ethyl N-mesylazidoformimidate [N3C(OEt)NMs] and ethyl azidoformate (N3CO2Et) with high asymmetric induction (>95%), while the corresponding cyclohexanone enamine gave ring contraction products. With the same azides the cyclopentanone enamine, prepared from (S)-2-(methoxymethyl)pyrrolidine gave N-substituted alpha-amino cyclopentanones in moderate enantiomeric excess. (C) 1997 Elsevier Science Ltd.