Solid and cystic pseudopapillary tumor of the pancreas: A case report.

Introduction: Solid and cystic pseudopapillary tumor of the pancreas is a rare tumor of the pancreas, for the first time described by Frantz et al. in 1959. The majority of patients are young females and most of them are asymptomatic.

Synthesis of thiazolidine-fused heterocycles via exo-mode cyclizations of vinylogous N-acyliminium ions.

Syntheses of thiazolidine-fused heterocycles via exo-mode cyclizations of vinylogous N-acyliminium ions incorporating heteroatom-based nucleophiles have been examined and discussed. The formation of (5,6)-membered systems was feasible with all nucleophiles tried (O, S and N), while the closing of the five-membered ring was restricted to O- and S-nucleophiles. The closure of a four-membered ring failed.

Choledochal cyst: presentation of the disease with a case report.

Choledochal cyst is a rare disease of the biliary tract. There are five main types of choledochal cysts with a few recognized sub-types. The etiology of choledochal cysts still is unclear.

Quantitative structure-retention relationship of new N-substituted 2-alkylidene-4-oxothiazolidines.

A quantitative structure-retention relationship (QSRR) was built to investigate the relationship between the structural descriptors of 23 newly synthesized N-substituted 2-alkylidene-4-oxothiazolidines and their chromatographic retention. Retention was investigated by means of the reversed-phase thin-layer chromatography (RP-TLC) on the C(18) and CN stationary phases, using methanol, acetonitrile, and tetrahydrofuran as organic modifiers. Full geometry optimization based on the Austin Model 1 (AM1) semi-empirical molecular orbital method was carried out and a set of physicochemical molecular descriptors was calculated from the optimized structures.

A base promoted cyclization of N-propargylaminopyridines. Synthesis of imidazo[1,2-a]pyridine derivatives.

A base promoted cyclization of the protected N-propargylaminopyridines was shown to be an efficient method for the preparation of imidazo[1,2-a]pyridine derivatives. The reactions were carried out with a small excess of base, at room temperature or slightly above producing the heterocyclic products in moderate to good yields. The stereoelectronic properties of substituents on the pyridine ring were shown to influence the cyclization process.

Structure-retention relationship study of diastereomeric (Z)- and (E)-2-alkylidene-4-oxothiazolidines.

Quantitative structure-retention relationship (QSRR) was developed for a series of the (Z)- and (E)-2-alkylidene-4-oxothiazolidine derivatives by the multiple linear regression (MLR) analysis. Full geometry optimization based on Austin Model 1 (AM1) semiempirical molecular orbital method was carried out and a set of physicochemical molecular descriptors was calculated from the optimized structures. In order to obtain useful experimental parameters, the lipophilic character of analytes was measured by RP-TLC, and lipophilicity parameters were correlated with physicochemical structural descriptors.

Ethyl 3-(6-phenyl-4λ-1,2-dithiolo[1,5-b][1,2,4]dithia-zol-2-yl)propanoate.

The title compound, C(15)H(15)NO(2)S(3), exists in a bicyclic form, with resonance contributions from two monocyclic forms, each without a second S-S bond. The trithiapentalene heterocyclic ring system is planar, with a mean deviation of 0.014 (2) Å from the mean plane, and is inclined to the plane of the attached phenyl ring at an angle of 17.