Ingrid Luyten

Reaction of heterocyclic thioamides with dimethyl acetylenedicarboxylate. Synthesis of novel 2-azolyl-5-methoxycarbonylmethylene thiazolin-4-ones

Abstract A systematic study of the reactions of dimethyl acetylenedicarboxylate (DMAD) with heterocyclic thioamides has been carried out and a number of new 2-isoxazolyl-( 8 ), imidazolyl-( 13a , b and 17a ), 1,2,3-triazolyl-( 13d , e ) and 1,2,3-thiadiazolyl ( 17b ) thiazolines have been prepared. The higher reactivity of the thioamide group in comparison with the amino group in these reactions has been established.

CYCLOHEXENE NUCLEIC ACIDS (CeNA) FORM STABLE DUPLEXES WITH RNA AND INDUCE RNASE H ACTIVITY

Cyclohexene nucleic acids (CeNA) were synthesized using classical phosporamidite chemistry. Incorporation of a cyclohexene nucleo-side in a DNA chain leads to an increase in stability of the DNA/RNA duplex. CeNA is stable against degradation in serum. A CeNA/RNA hybrid is able to activate E. Coli RNase H, resulting in cleavage of the RNA strand.

Synthesis and study of the rearrangements of 5-(1,2,3-triazol-4-yl)-1,2,3-thiadiazoles

Abstract A method for the synthesis of heterocyclic ring conjugates containing 1,2,3-thiadiazole and 1,2,3-triazole nuclei was elaborated. The mechanism of rearrangement (effect of substituents and solvents) was investigated by NMR spectroscopy. A novel domino-type rearrangement involving both heterocycles was discovered.

Synthesis and properties of O-beta-D-ribofuranosyl-(1"-2')-adenosine-5"-O-phosphate and its derivatives.

Abstract The synthesis of O-β-D-ribofuranosyl-(1″-2′)-adenosine-5″-O-phosphate and its suitably protected derivative for oligonucleotide synthesis have been developed.

Stereo- and regiochemistry in the (asymmetric) cycloaddition reaction of 5-chloro-2(1H)-pyrazinones with cyclic and monosubstituted alkenes and with a N-acryloyl substituted chiral auxiliary

Abstract The cycloaddition of 5-chloro-2(1 H )-pyrazinones 1 with various dienophiles was used to generate the corresponding 2,5-diazabicyclo[2.2.2]octanes. Following reduction or hydrolysis of the bridged adducts, the regio- and stereochemical structure was determined by analysis of the coupling and NOE patterns in the 1 H NMR spectra. With symmetric dienophiles the endo adducts are formed exclusively. The regiochemistry for the reaction of 1 with methyl acrylate and ethyl vinyl ether, and the asymmetric induction found with the N -acryloyl substituted chiral auxiliary (4 S )-4-isopropyl-1-methyltetrahydro-2 H -imidazol-2-one, largely depend on the electron donating or attracting properties and size of the 3-substituents of 1 .

Synthesis and antiviral activities of some new 5-heteroaromatic substituted derivatives of 2'-deoxyuridine

Abstract Eight new 5-heteroaromatic substituted analogues of 2′-deoxyuridine have been synthesized and evaluated for their inhibitory properties against a panel of different viruses. Several analogues containing a substituted thiophene moiety proved to be highly selective against herpes simplex virus type 1 (HSV-1).

Synthesis of novel thiazolidin-4-ones by reaction of malonthioamide derivatives with dimethyl acetylenedicarboxylate

Novel 2,5-dimethylenethiazolidin-4-one derivatives have been prepared by reaction of malonthioamide derivatives with dimethyl acetylenedicarboxylate. These compounds exist as separate (E,Z)- and (Z,Z)-isomers or as a mixture. The (E,Z)-isomer is formed as the initial product which transforms to the (Z,Z)-isomer under mild conditions. The structures of the obtained compounds have been confirmed by IR and NMR spectroscopy.

Regioselectivity of the synthesis of 2-pyrazolinylthiazoles by reacting 2-hydrazinothiazoles with unsymmetrical beta-diketones

Novel 2-pyrazolinylthiazoles 1 are prepared by reaction of 2-hydrazinothiazoles 2 with 1,3-dicarbonyl compounds of type 3. The conditions of the aromatization of 1 to 2-(3-aryl-5-trifluoromethylpyrazol-l-yl)thiazoles 4 have been investigated.