Fernando Tomé

Diels–Alder reactivity and some synthetic applications of (E)-1-(3-indolyl)-3-tert-butyldimethylsiloxy-1,3-butadienes

Abstract The preparation of (E)-1-(3-indolyl)-3-tert-butyldimethylsiloxy-1,3-butadienes and their Diels–Alder reaction with selected dienophiles at room temperature is described. The utility of these heteroaryldienes for the construction of different (3-indolyl)-planar systems is shown by the synthesis of a grooved analogue of arcyriaflavin A.

Synthesis and cytotoxic activity of phenyl-hexahydropyrrolo[3,4-c]carbazoles

Abstract A synthetic methodology for the preparation of fused carbazole derivatives has been developed. The presence of a trimethoxyphenyl substituent and the hexahydropyrrolo[3,4-c]carbazole system produced a new family of compounds, that display cytotoxic activity.

Unusual allylic acetoxylations of silyl enol ethers with lead(IV) acetate

Abstract 1-Siloxycyclohexenes, bearing an oxy group at position 3 and a syn -disposed cis -fused ring at positions 4 and 5, undergo regio- and stereo-selective acetoxylations (at position 6) in the presence of lead(IV) acetate.

Stereochemical control of perhydroindanes for the synthesis of cardenolide analogs

Abstract The control of the stereochemistry at C-1 of cis-perhydroindane compounds, required for the synthesis of cardenolide analogs, has been achieved by epimerization of the dithiane derivative at C-5. Molecular modeling of this kind of compounds predicted the higher stability of the C-1-β-epimer in this and other derivatives, instead of the usually more stable C-1-α-epimer in the natural cardenolides and other calculated compounds.

New 7-aryl analogues of anthracyclines : Synthesis and cytotoxic activity of (±)-7-(3,4,5-trimethoxyphenyl)-7-deoxyidarubicinone

Abstract The synthetic methodology for the preparation of 7-aryl-7-deoxyanthracyclinones, a new class of anthracycline analogues, is described. Readily available materials are easily transformed into the key intermediate ketone, that is converted into bent and planar tetracyclic compounds. Cytotoxic studies of the final and intermediate products reveal a moderate activity of bent products and a lack of activity of planar products, thus supporting a non-intercalating mechanism for their cytotoxic activity.

One Carbon Elongation of the Hajos-Parrish Ketone. Synthesis of (+)-(3aS,7aR)-Octahydro-3a-hydroxy-7a-methyl-1-methylene-5H-indene-5-one

Abstract The dificulties encountered for the C-1 methylenation of Hajos-Parrish (1) and Hajos-Wiechert (2) ketones, were overcome by the use of Conia reaction on their C-5 dithiane derivatives.

Reactivity of 4-tert-butyldimethylsiloxy-1,2,3,6-tetrahydropyridines with hydrazines.

The reactivity of 6-(nitrophenyl or trimethoxyphenyl)-4-tert-butyldimethyl- siloxy-1,2,3,6-tetrahydropyridine derivatives with hydrazines under acid conditions is described. The structure of the products isolated - hydrazones, pyrazolines or pyridazinones - depended on the conditions used. In addition, a systematic study of the reaction outcomes was carried out by introducing variations on the substituents of the tetrahydropyridine ring.

Synthesis of B, B-dinor-B-secosteroids as potential cardenolide analogues

Abstract A novel chemical construction of B,B-dinor-B- seco steroids as simplified cardenolide analogs, starting from the Hajos–Parrish diketone was developed. The synthesis of the equivalent of the steroid A ring was carried out through a Diels–Alder reaction between an appropriate hydroindenyl acrylate derivative and Danishefskys diene.