Table of Contents

Abstract: Substituted homoallylic alcohols have been synthesised both by [2,3]-Wittig rearrangement of unsymmetrical bis-allylic ethers and reaction of alkenyl chloromethyl oxiranes with Mg/THF. These substrates were then oxidized using four different oxidants. When the substituted homoallylic alcohols were oxidized with pyridinium chlorochromate or zinc chlorochromate nonahydrate the corresponding carbonyl compounds were produced. The same substrates formed the corresponding allylic oxidation products together with epoxidation products when oxidized with t-BuOOH. When and t-BuOOH and catalytic amounts of OsO₄ were used the allylic oxidation reaction was prevented and the only products formed were those in which the substituted double bond was epoxidized.

Abstract: Nimonol (1), a tetranortriterpenoid isolated from the leaves of Azadirachta indica A. Juss (Meliaceae), upon photolysis undergoes both Diels-Alder and ene reactions with singlet oxygen at different sites leading to 14,15,20,21-diepoxy-23-nimonolactone (3), along with nimonolide (4), which have been well-characterised. The novelty of the reported reactions lies in hitherto unreported formation of an α-epoxide in the ring D in tetranortriterpenoids. The photoproduct 4 exhibited antifeedancy comparable to that of azadirachtin-A, the most potent antifeedant constituent isolated from neem.

Abstract: It has been shown that N-(3-oxoalkyl)chloroacetamides (1) can be converted into cis-3,4-epoxypiridin-2-ones (2) upon treatment with t-BuOK in a t-BuOH-C₆H₆ solution due to a resulting intramolecular Darzens reaction. It has been found that under kinetically controlled reaction conditions (NaOH/C₆H₆), besides the intramolecular Darzens reaction an intramolecular alkylation takes place.

Abstract: A new, universal and diastereospecific method has been developed for the synthesis of 5,6-dihydropyridin-2(1H)-ones, 1,5,6,8,8a-hexahydroisoquinolin-3(2H)-ones and 4a,5,6,7,8,8ahexahydroquinolin-2(1H)-ones (4) based on the intramolecular Wittig cyclization of the triphenyphosphonium salts 2 derived from the N-(3-oxoalkyl)–chloroacetamides 1.

Abstract: (-)-Carvone (3) has been efficiently transformed into (-)-3β-hydroxycarvone (1), which is expected to be a useful synthon or chiral template in the synthesis of natural molecules. This short and efficient synthesis of compound 1 involves regioselective and stereoselective α-hydroxylation of carvone via the trimethylsilyl-dienyl-ether derivative.

Abstract: Condensations of anhydrides and quinaldine derivatives are accelerated by microwave irradiation under solvent free conditions in the presence of silica gel as catalyst.

Abstract: Two potentially heptadentate (N4O3) tripodal Schiff-base ligands: tris(3-(salicylideneimino)propyl)amine (H₃L1) and tris(3-(4’-hydroxysalicylideneimino)-propyl)amine (H₃L2) have been prepared and characterized by various spectroscopic methods (IR, FAB-MS, NMR). They are derived from the condensation reactions of tris(3-aminopropyl)amine (tpt), with 3 equivalents of either salicylaldehyde or the ringsubstituted salicylaldehyde, 4-hydroxysalicylaldehyde. The nickel(II) and copper(II) complexes of H₃L1 were obtained from the its reactions Ni(II) and Cu(II) salts in absolute methanol. These complexes were studied by IR and FAB-Mass spectrometry.

Abstract: Thieno[2,3-d]-1,2,3-thiadiazoles (1) react with carbon disulfide in a "Matryoshkatype" double compartment autoclave [1] to yield thieno[2,3-d]-1,3-dithiol-2-thiones (2). With BH₃/Me₂S the cyclic trithiocarbonate (2d) is cleaved and the product characterized after methylation as 4b. Compounds 7a and 7b are prepared via the thieno[2,3-d]-1,3-dithiolium salts (6) followed by NaBH4-reduction.

Abstract: The reactions of acenaphthenequinone and its derivatives with different nucleophiles, organic and inorganic reagents are reviewed. This survey also covers their oxidation and reduction reactions, in addition to many known reactions such as Friedel Crafts, Diels-Alder, bromination and thiolation.

Abstract: The thermal decomposition of imidoyl azides (ArO-C=N-Z)-N3, (Ar = p-NO₂-C₆H₄-, p-Br-C₆H₄-, p-Cl-C₆H₄-, p-C₆H₅-, p-CH₃-C₆H₄-, 2,4-dimethyl-C₆H₃-, 2,4,6-trimethyl-C₆H₂-, p-CH₃O-C₆H₄- and Z = p-CH₃-C₆H₄-SO₂-, 2,4,6-trimethyl-C₆H₂-SO₂-,CN) in the solid phase and in anisole has been studied in detail. The sensitivity of nitrenes and nitrene precursors (imidoyl azides) towards substitution changes in the aryloxy (ArO) and Z moieties is examined.

Abstract: Thirteen previously unreported substituted phenyl N-(2-hydroxybenzyl)-Nmethylcarbamates were prepared by the reaction of substituted 2-hydroxybenzyl-Nmethylamines with phenyl chlorocarbonates. They were identified by their ¹H- and ¹³C-NMR spectra.

Abstract: A strategy for a new type of platform for chemoinformatics software development and its first implementation are presented. The basic task of such a platform is to apply sequences of computational methods to high numbers of molecules. The implementation presented is based on four major components: (a) the application manager, responsible for running programs and for data management; (b) executable applications that supply limited pieces of functionality; (c) syntax definitions for data and control files and (d) the runtime library which comprises routines for data handling and user interface. This simple concept is implemented in the software package marvin. Different computational methods are available within marvin, including parts of commercial software packages (e.g. molecular modeling, bioinformatics, statistics, etc.) as well as newly developed and innovative algorithms. The basic layout of marvin is described and a simple example illustrates its application.

Abstract: Aldoxime derivatives of 4H-pyran-4-ones 4-7a,b have been synthesized by the reaction of di(aminoxymethyl) pyranones 3a,b with aromatic aldehydes.

Abstract: An acylated kaempferol glycoside, namely kaempferol-3-O-α-L-(2”,3”-di-E-pcoumaroyl)-rhamnoside (1) was isolated from the flowers of Foeniculum vulgare Mill. and F. dulce DC. It is thus isolated for the first time from family Apiaceae. In addition, the different organs of both plants afforded six flavonoid glycosides - namely afzelin (kaempferol-3-O-α-L-rhamnoside) (2), quercitrin (3), isorhamnetin-3-O-β-D-glucoside (4), isoquercitrin (5), rutin (6), and miquelianin (quercetin-3-O-β-D-glucuronide) (7). Structure elucidation of the above mentioned flavonoids was achieved by UV, ¹H- and ¹³C-NMR, ¹H-¹H COSY, HMQC and EI-MS.

Abstract: Different types of novel 1,2-disubstituted 1,2-dihydro isoquinolines were synthesized by addition reactions of organolithium, alcoholates and borohydride reagents with various isoquinolinium salts. The leaving group character of the isoquinoline moiety was also evidenced.

Abstract: Manganese (III) meso-tetrakis(p-sulfonatophenyl)-β-octabromoporphyrin supported on Amberlite IRA-400 [Mn(Br₈TPPS)-Ad-400] is a robust and efficient catalyst for epoxidation of alkenes and hydroxylation of alkanes with sodium periodate at room temperature.

Abstract: This review presents the phytochemical constituents of the genus Plectranthus reported up to 1999. Only a tetrameric derivative of caffeic acid was isolated from P. japonicus, but a group of long-chain alkylphenols, of possible taxonomic significance in the genus, was also isolated. As a genus of the subfamily Nepetoideae, Plectranthus is free from iridoid glycosides and rich in essential oil (i.e. > 0.5% volatile oil on a dry weight basis). Diterpenoids are the more common secondary metabolites in Plectranthus. The majority of them are highly modified abietanoids. This seems to be similar to the pattern of diterpenoids observed for Salvia, but no clerodane diterpenoids were found in Plectranthus.

Abstract: We review in this article some of our work which has been published over the last fifteen years in the area of 1,3-dipolar cycloaddition reactions of substituted benzyl azides with acetylenic compounds to form the corresponding 1,2-3-triazoles. Several triazole derivatives were transformed into triazolopyridazine and triazolo-1,3,4-oxadiazole derivatives upon their reactions with hydrazine.

Abstract: The synthesis of a new spirolactone is described. The title compound is obtained as a white solid in 46% yield from 3-(4-hydroxy-2-methoxyphenyl)propanoic acid using [Bis(trifluoroacetoxy)iodo]benzene (PIFA) as the oxidant.