RESUMO
[structure] The enantioselective total synthesis of (+)-preussin, a potent antifungal agent, has been achieved. The key steps are a Pd(0)-catalyzed oxazoline-forming reaction from L-phenylalanine, hydrogenolysis, and subsequent diastereoselective reductive cyclization of the intermediate aminoketone to pyrrolidine using Pearlman's catalyst.
Assuntos
Anisomicina/análogos & derivados , Antifúngicos/síntese química , Anisomicina/síntese química , Catálise , Ciclização , Hidrogenação , Oxazóis/síntese química , Oxazóis/química , Oxirredução , Paládio , Fenilalanina/química , EstereoisomerismoRESUMO
Stereochemical isomers with hydroxy groups were synthesized by reacting 2-(dimethoxymethyl)cyclohexanone with propargylmagnesium bromide. The stereo chemical structures were identified by NMR spectral interpretation and the geometry optimization. To assist the NMR interpretation, geometry optimization based on semi-empirical AM1 and PM3 methods was applied. Throughout this study, the structures of the two isomers were all determined and 1H and 13C NMR spectra were fully assigned. It was proven that the less polar isomer is an axial alcohol and the more polar one is an equatorial alcohol.
Assuntos
Alcinos/síntese química , Propanóis/síntese química , Alcinos/química , Indicadores e Reagentes , Isomerismo , Espectroscopia de Ressonância Magnética , Conformação Molecular , Propanóis/químicaRESUMO
Total synthesis of (+/-)-homoepibatidine (2), which contains the 8-azabicyclo[3.2.1] octane ring system, was achieved by using palladium-catalyzed Heck-type coupling reaction from 3.
Assuntos
Analgésicos não Narcóticos/síntese química , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Piridinas/síntese química , Indicadores e Reagentes , PaládioRESUMO
Stereoselective synthesis of (+/-)-epibatidine analog 2, which contains the 8-azabicyclo[3.2.1]octane ring system, was achieved by using palladium-catalyzed Heck-type coupling reaction from 3.
Assuntos
Analgésicos não Narcóticos/química , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Agonistas Nicotínicos/química , Paládio/química , Piridinas/síntese química , EstereoisomerismoRESUMO
Purine nucleosides were chlorinated by the reaction of acyl chloride in DMF with MCPBA under mild conditions with moderate yields. And, satisfactory method for the synthesis of ribonucleoside-3',5'-cyclic phosphates and its characterization by(1)H and(13)C nmr spectroscopy is described.
RESUMO
The synthesis of 3a, 3b, 7a and 7b from Benzothiazepinone and 1,4-dihyropyridine derivatives is described. Benzothiazepinone and 1,4-dihydropyridine derivatives were prepared according to literature procedure. The key reactions involve esterification and amidation of benzothiazepinone and 1,4-dihydropyridine derivatives.
