Air oxidation of hexahydrobenz[f]indolizine-3,10-diones in MeOH/MeONa yields alcohols, which are easily and selectively transformed, in very good yields, to succinimides, isoquinoline propanoic acids or dehydrated to ene lactams.

Reductive alkylation of Meldrum's acid with acetaldehyde can give, depending on the experimental conditions, either a new dimer (5-[3-(2,2-dimethyl-4,6-dioxo-1,3-dioxan-5-yl)butyl]-2,2-dimethyl-1,3-dioxane4,6-dione) or ethyl Meldrum's acid (2,2-dimethyl-1,3-dioxane-4,6-dione). A best way to obtain this latter product is synthesis of 1-ethoxyethylidene Meldrum's acid from reaction of Meldrum's acid with triethyl orthoacetate, followed by a sodium borohydride reduction.

Depending upon the conditions, heating of 1,10a-dihydro-2H,5H-pyrrolo-[1,2-b]isoquinoline-3,10-diones in polyphosphoric or hydrochloric acid gives rise to hydride transfer and oxidative processes. Mono or dienyl lactams, or mixtures of dimers and acids or hydroxyacids of the isoquinotine series were thus formed. Procedures leading specifically to each of these products have been found.

Reaction of acetylene dicarboxaldehyde rnonoacetal with substituted Meldrum's acid leads good yields in 2-pyranolies-4-carboxaldehydes substituted in position 3. (C) 2004 Elsevier Ltd. All rights reserved.

During attempted Friedel–Crafts cyclization of some arylmethyl pyroglutamic acids or of N-phenacyl prolines, decomposition of the activated form of the acid have been observed, giving new heterocyclic systems. This general decarboxylation occurred when there are difficulties to realize a Friedel–Crafts cyclization and is explained by geometrical or electronic considerations.

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Polymers based upon hydroquinone–quinone redox system were prepared by the addition of hydroquinone and methylhydroquinone to parachloromethylstyrene. Others were obtained by vinylation of halogenated compounds and polymerization of monomers containing the redox system. In the last case, composition and structure of macromolecules are known with increased certainty and so, they are readily characterized. For the first time, preparation and polymerization of monomers are realized with good yields. By using these macromolecules to remove oxygen from water, it was established that redoxite properties of Electron Transfer Polymers (ETP) have been closely related to the number of redox functions on the polymer matrix. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 223–229, 2001

An economical way to obtain new monomers, precursors of electron transfer polymers, is described. These monomers were obtained by a Heck reaction between amino or halogeno-2,5-dimethoxydiarylmethane and methylacrylate. Different routes for the ionic reduction of various acetophenones to the corresponding diarylmethanes were studied. The yields and the nature of the by-products was stongly dependent upon the reaction conditions.

Benzylation of p-dialkoxybenzenes can be achieved through the use of modified montmorillonite K10 clay. For the first time, syntheses of nitro-diarylmethanes were obtained by Friedel-Crafts alkylation with good yields. In the case of p-methoxymethyl phenyl ether and phenyl ester, selectivity favoring Fries rearrangement over benzylation is reported.

Various alkyl-substituted p-dimethoxybenzenes (ArH) react readily with nitric acid and sulfuric to form nitro-products (ArNO 2 ). When the nitric acid is used in excess, the nitro-product react via either nitration to dinitro-compound (Ar(NO 2 ) 2 ) or via oxidative demethylation to nitro- p-quinone (Q). As such, the competition between the nitration, polynitration and oxidative dealkylation is effectively modulated by the added nitric acid and the alkyl-substituted p-dimethoxybenzenes.

The complete structural analysis of 1-[(4-methoxyphenyl)-(3,4,5-trimethoxyphe- nyl)methyl]naphtalene 5a and 1-[(2,5-dimethoxyphenyl)-(3,4,5-[GRAPHICS]FIG. 1. Structure of N-(1-naphtyl-(3,4,5-trimethoxyphenyl)methyl)pyroglutamic acid 1 and benzofluorene 2.trimethoxyphenyl) methyl]naphtalene 5b, prepared by alkylation of 1-[chloro-(3,4,5-trimethoxyphenyl) methyl]naphtalene without by-products such as benzofluorene 2, may be accurately determined by H-1, C-13 NMR and 2D NMR analysis.

Tetrahydro-2H-pyrrolo[1,2-c]quinazoline-3-ones are easily obtained from the Friedel-Crafts cyclization of N-arylaminomethyl pyroglutamic acids. This reaction occurrs via an acyliminium salt formed by decarboxylation of the acid function.

The ionic hydrogenation of diarylcarbinols by triethylsilane, in the presence of catalytic amount of triflic acid proceeds via dibenzhydryl ethers. These ethers do not disproportionate to benzophenones and diphenylmethanes but are reduced by triethylsilane to diarylmethanes.Key words: catalytic reduction, benzhydrols, dibenzhydryl ethers, triethylsilane.

Reduction of substituted benzophenones 1 with sodium borohydride and trifluoro-acetic acid yields diphenylmethanes 3 as well as dimers 5 and 6. The complete structure of these substituted diphenylmethane dimers 5 may be accurately determined by H-1, C-13, 2D NMR analysis, and a mechanism for their formation is suggested.

Heck vinylation reactions of different anilines were performed with vinylacetate by using palladium chloride and copper nitrate intercalated montmorillonite K10 clay as catalyst. The substituted methylcinnamates were obtained in good yields without simultaneous side reaction to stilbenes.

Starting from 2-thioxoquinazolin-4-one, the synthesis of 2-amino-4(3H)-one derivatives, structurally related to potassium channels openers pinacidil and diazoxide, is described.

The Friedel-Crafts cyclisation of N-benzhydrylpyroglutamic acids whose aromatic rings are substituted by methoxy or methylenedioxy groups gives podophyllotoxin analogs whose lactone ring was changed to a lactam.

Several 1,3,4-oxadiazoles were synthetized by cyclization of N,N'-diacylhydrazines catalyzed by palladium(0). Water formed during the reaction is responsible for the hydrolysis of the products. To avoid it, we introduced benzoic anhydride into the medium and obtained an increased yield of oxadiazoles.