RESUMEN
A concise approach to the cephalotaxine CDE ring skeleton based on the intramolecular formal [5 + 2] photocycloaddition of cyclopentenyl-substituted maleimides is described. An investigation of the diastereoselectivity afforded by various protected alkoxy groups demonstrated that the best selectivity (3.5:1) was afforded by the free hydroxyl group, strongly suggesting a hydrogen-bonded excited state. Reaction: see text.
Asunto(s)
Antineoplásicos Fitogénicos/síntesis química , Harringtoninas/síntesis química , Maleimidas/química , Antineoplásicos Fitogénicos/química , Harringtoninas/química , Homoharringtonina , Modelos Moleculares , Conformación Molecular , Fotoquímica , Hojas de la Planta/química , Plantas Medicinales/químicaRESUMEN
Derivatives of naringenin have been synthesized with organometalcarbonyl reporting groups for IR spectroscopy attached at C-2, C-3', or C-6, and the products have been tested for the induction of nod gene expression using a Rhizobium leguminosarum strain which contains the Escherichia coli lacZ (beta-galactosidase) gene fused to nodABC. Derivatives with an OMe substituent within the reporting group moiety showed residual gene induction activity.
