Remigiusz Zurawinski

A new synthesis of (±)-sarkomycin from a β-ketophosphonate

Abstract The total synthesis of (±)-sarkomycin starting from diethyl 2-oxopropanephosphonate is reported. The key step in this synthesis includes the Horner-Wittig reaction of 2-diethoxy-phosphoryl-3-carboxy-cyclopentanone with formaldehyde

New phosphonate-mediated syntheses of cyclopentanoids and prostaglandins*

This account outlines the results obtained in the authors laboratory on the application of phosphonate reagents in the synthesis of biologically active cyclopentanones and cyclopentenones. The synthesis and reactivity of 3-phosphorylmethyl-cycloalkenones is discussed as a platform for developing the first synthesis of enantiomeric isoterreins as well as the synthesis of racemic and optically active prostaglandins B 1a. A different strategy for the total synthesis of racemic and enantiomeric forms of sarkomycin and rosaprostol is described which involves in a key step intramolecular carbenoid cyclization of the corresponding a-diazo-b-ketophosphonates.

Fluorescence and confocal imaging of mammalian cells using conjugated oligoelectrolytes with phenylenevinylene core

Over the last few years, considerable efforts are taken, in order to find a molecular fluorescent probe fulfilling their applicability requirements. Due to a good optical properties and affinity to biological structures conjugated oligoelectrolytes (COEs) can be considered as a promising dyes for application in fluorescence-based bioimaging. In this work, we synthetized COEs with phenylenevinylene core (PV-COEs) and applied as fluorescent membranous-specific probes. Cytotoxicity effects of each COE were probed on cancerous and non-cancerous cell types and little to no toxicity effects were observed at the high range of concentrations. The intensity of cell fluorescence following the COE staining was determined by the photoluminescence analysis and fluorescence activated cell sorting method (FACS). Intercalation of tested COEs into mammalian cell membranes was revealed by fluorescent and confocal microscopy colocalization with commercial dyes specific for cellular structures including mitochondria, Golgi apparatus and endoplasmic reticulum. The phenylenevinylene conjugated oligoelectrolytes have been found to be suitable for fluorescent bioimaging of mammalian cells and membrane-rich organelles. Due to their water solubility coupled with spontaneous intercalation into cells, favorable photophysical features, ease of cell staining, low cytotoxicity and selectivity for membranous structures, PV-COEs can be applied as markers for fluorescence imaging of a variety of cell types.

α-Phosphoryl Cyclopentanones as Possible Intermediates in the Total Synthesis of Sarkomycin

Abstract In an effort to synthesize sarkomycin 1 trans-2-diphenylphosphinoyl-3-tris (methylthio) methyl-cyclopentanone 7 and trans-2-diphenylphosphinoyl-3-carbo-methoxy-cyclopentanone 8 were prepared. The Horner-Wittig reaction of the latter with formaldehyde failed. (±)-Sarkonycin 1 was prepared by a sequence of reactions starting from diethyl 2-oxopropanephosphonate. The key steps in this synthesis involve the intramolecular carbenoid cyclization of 1-diazo-2-oxopropanephosphonate 10 and the Horner-Wittig reaction of 2-diethoxyphosphoryl-3-carboxy-cyclopentanone 12 with formaldehyde.

THE E⇌Z ISOMERIZATION OF 1-METHYLSULFANYLPROPENOIC N-ARYLTHIOAMIDES

Abstract 1-Methylsulfanylpropenoic N-arylthioamides 2 were shown to undergo the two way F/Z isomerization triggered by heat, light and the oxygen and sulfur nucleophiles.