The synthesis of the spiro(4,5)decane system is of interest because it constitutes the basic skeleton of the acoranic sesquiterpenes [1]. In this paper we wish to report a stereospecific synthesis of a promising precursor (1) of some of these natural products. According to literature [2] cyclohexanones asubstituted with a co-carboxyalkyl chain yield diketo-spiro systems on treatment with polyph...

The title compound, C22H22N2O5, contains two conformationally similar mol-ecules (A and B) in its the asymmetric unit (r.m.s. overlay fit for the 29 non-H atoms = 0.194 Å). In each mol-ecule, the lactone ring has an envelope conformation with the spiro C atom as the flap. In the crystal, A+A and B+B inversion dimers linked by pairs of N-H⋯O hydrgen bonds occur; in both cases, R 2 (2)(8) loops a...

Perpendicular orientation of the electron donor in relation to the acceptor in the ground state seems to contribute significantly to high rate constants of the photoinduced intramolecular electron transfer (PET) in electron donor-acceptor (DA) type molecules [1]. A very interesting class of molecules in this respect are systems build around a spiro-type carbon atom, separating mutually orthogon...

Radical-radical cross coupling reactions of photoexcited 9-fluorenones have been accomplished for the first time, leading to the synthesis of 9-alkyl, pyrollidinyl and spiro-THF derivatives of 9-fluorenones. The method also reveals, for the first time, the behaviour of ketyl radicals in decarboxyaltive alkylation and ring expansion reactions.

The title compound, C(33)H(46)O(7), is an unusual oxydation product of the therapeutic agent glycyrrhetinic acid that has, in comparison to the latter, a distinctly altered triterpene structure with one five- and four six-membered carbocycles complemented by a γ-lactone ring with a spiro-junction and a ring double bond. The junction between the five-membered ring C, a cyclo-penta-none ring, and...

accumulating evidence indicates that aldosterone plays a critical role in the mediation of oxidative stress and vascular damage. nadph oxidase has been recognized as a major source of oxidative stress in vasculature. however, the relation between nadph oxidase in aldosterone-mediated oxidative stress in endothelial cells remains to be ascertained. the present study aimed to investigate the rele...

Heterocyclic compounds containing β-lactum structure with different hetero atoms are found to show biological activities1. In the present work, it has been synthesized the semicarbozone and thiosemicarbozone derivatives of 3-methyl-2,6-diphenylpiperidin-4-one followed bycyclisation to get the spiro compounds. These spiro compounds. The spiro products have been characterized by C,H,M analysis, I...

the development of multicomponent reactions (mcrs) designed to produce elaborate biologically active compounds has become an important area of research in organic, combinatorial, and medicinal chemistry. a comparative study of the synthesis of new bis-spiro-oxindolo(pyrrolizidines/pyrrolidines) ring systems by the cycloaddition of azomethine ylides generated by a decarboxylative route from sarc...