RESUMO
A facile strategy for the annulation of 2,6-dicyanoaniline moiety to steroidal A/B-ring is described from base catalyzed and microwave-promoted reaction of steroidal 3-keto-2-hydroxymethylenes with malononitrile in high yields. The generality of the reaction has been extended to non-steroidal cyclic and aliphatic ketohydroxylmethylenes.
Assuntos
Compostos de Anilina/química , Micro-Ondas , Esteroides/química , Estrutura Molecular , Esteroides/síntese químicaRESUMO
The preparation of ring-A fused pyrimidines at the steroidal 2,3-position is herein described. The novel steroidal pyrimidines were prepared from the solid phase three-component reaction of 2-hydroxymethylene-3-keto steroids, arylaldehydes and ammonium acetate under microwave irradiation.
Assuntos
Micro-Ondas , Pirimidinas/química , Esteroides/síntese química , Acetatos/química , Aldeídos/química , Cetosteroides/química , Esteroides/químicaRESUMO
A facile strategy for the preparation of A-ring fused pyridosteroids has been accomplished in high yields by the reaction of Vilsmeier reagent (chloromethyleneiminium salt) with steroidal A-ring enamides (2- and 3-ene) under thermal conditions. The structure of 6'-chloro-5alpha-cholest [3,2-b]pyridine was determined by X-ray analysis.
Assuntos
Química Orgânica/métodos , Piridinas/química , Piridinas/síntese química , Esteroides/química , Esteroides/síntese química , Anaerobiose , Cristalografia por Raios X , Temperatura Alta , Conformação MolecularRESUMO
The preparation of ring-A fused steroidal dehydropiperazine at the 3,4-position is herein described. The novel steroidal dehydropiperazines were prepared from the annulation reaction of ethylenediamine with 3-keto-4-en steroids in a one-pot reaction under microwave irradiation. The key step involves base catalysed aerial oxidation of the C-6 methylene group followed by cyclocondensation of ethylenediamine via Michael addition reaction.