A. Ricca

Alkylation of indole sodium salt as ambifunctional nucleophilic system

Abstract The relationship between the structure of alkyl halides and the relative reactivity of nucleophilic centers existing in an ambifunctional nucleophilic system and in particular the alkylation reactions of the indole sodium salt in THF with primary, secondary, tertiary, allyl and benzyl halides has been investigated. In the course of alkylation of the indole salts, the reactivity of the less electronegative center (position 3 of the indole nucleus) increases the higher the SN 1 character of the reacting species and the greater the interaction of the cation with the ambient indole anion. This is in accordance with the results reported for pyrrole, enol and phenol ambident systems. For a number of alkyl, allyl and benzyl indole derivatives, the methods of separation and the spectrographic characteristics (IR, UV, NMR) of pure products are reported.

New aspects in the hydrogenolytic opening of 2-isoxazolines

Abstract It has been observed that the hydrogenolytic opening of 2-isoxazolines depends on the substituents present in positions 3 and 5. The hydrogenolysis on 10% Pd/C of 2-isoxazolines, substituted in position 3 with carbonyl or car☐yl groups and in position 5 with an aromatic group, gives oximes, in contrast to other isoxazoline derivatives. From the 5-aryl-2-isoxazolines it is possible to obtain aminoalcohols in ethanol and oximes in acetic acid.

Phenol compounds from isoxazoles, considered as masked β-polyketones

Methylen-bis-isoxazole (Ia)-(Ic) werden zu den Diketon-bis-enaminen (II) hydriert und dann sauer zu den Tetraketonen (III) verseift, die bereits unter Reaktionsbedingungen zu den isomeren Acetophenon-iminen (IV) cyclisieren und in die iso= ( 1?! meren Acetophenone (V) und (VI) ubergefuhrt werden konnen.

Nitrile Oxide-BF3 complex as electrophilic moiety towards aromatic systems: Stereospecific synthesis of oximes

Abstract Aromatic Oximes are obtained stereospecifically by action of Nitrile Oxide-BF 3 complexes on Aromatic Compounds.

PHENOL COMPOUNDS FROM ISOXAZOLES, CONSIDERED AS MASKED BETA‐POLYKETONES

Methylen-bis-isoxazole (Ia)-(Ic) werden zu den Diketon-bis-enaminen (II) hydriert und dann sauer zu den Tetraketonen (III) verseift, die bereits unter Reaktionsbedingungen zu den isomeren Acetophenon-iminen (IV) cyclisieren und in die iso= ( 1?! meren Acetophenone (V) und (VI) ubergefuhrt werden konnen.

Synthesis of tris and tetraisoxazole compounds

The syntheses of new tris (XII) and tetraisoxazole compounds (XIII and XIV) are reported; all synthons have been described. New isoxazole chlorooximes (V and VIII) have been prepared for this purpose and their behavior was examined.

New aspects of nitrile oxides chemistry

Abstract Reactivity of nitrile oxides (1) towards both dimerization and cycloaddition with dipolarophiles can be inhibited by catalytic amount of tris-(4-bromophenyl)-aminium hexachloroantimonate and subsequently restored.

SYNTHESIS OF 1,3-PHENYLENEDIAMINES FROM 3,3′-METHYLENEDIISOXAZOLES

Bei der katalytischen Hydrierung der Methylendiisoxazole (I) entstehen die Enaminketone (II).