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endo-Mode cyclizations of vinylogous N-acyliminium ions as a route to the synthesis of condensed thiazolidines
(Oxford : Pergamon-Elsevier Science Ltd, 2011)
endo-Mode cyclizations of vinylogous N-acyliminium ions incorporating heteroatom-based nucleophiles have been examined as a route to the synthesis of condensed thiazolidines. The scope of these reactions and stereochemical ...
Studies of the regioselective ring-opening closing mode of functionally different thiazolidine type enaminones: en route to the synthesis of trithiaazapentalene derivatives
(Oxford : Pergamon-Elsevier Science Ltd, 2013)
Trithiaazapentalene derivatives were prepared by the reaction of 2-alkylidene-4-oxothiazolidines with Lawesson's reagent. They are classified as two structurally different trithiaazapentalene compounds that have different ...
5,10:13,14-Disecosteroids: novel modified steroids containing 10- and 9-membered rings
(Oxford : Pergamon-Elsevier Science Ltd, 2009)
In this paper a synthetic pathway to the modified 5,10:13,14-bisfragmentation cholestane derivatives 8-14 is described. The synthesis involves introduction of the 5α- and 14α-hydroxyl groups in the cholestane molecule and ...
Regioselective synthesis of 1,3-thiazines by sequential 4-oxothiazolidine to 1,2-dithiole to 1,3-thiazine transformations: role of intramolecular non-bonded S/O interactions
(Elsevier, 2007)
A new synthetic approach to 2,3-dihydro-4H-1,3-thiazine derivatives based upon reductive rearrangement of 1,2-dithiole-3-ylidene thiones has been developed. In turn, the 1,2-dithiole derivatives were prepared by an efficient ...
Regioselective synthesis of 1,3-thiazines by sequential 4-oxothiazolidine to 1,2-dithiole to 1,3-thiazine transformations: role of intramolecular non-bonded S/O interactions
(Elsevier, 2007)
A new synthetic approach to 2,3-dihydro-4H-1,3-thiazine derivatives based upon reductive rearrangement of 1,2-dithiole-3-ylidene thiones has been developed. In turn, the 1,2-dithiole derivatives were prepared by an efficient ...
Transformations of 2-alkylidene-4-oxothiazolidine vinyl bromides initiated by bromophilic attack of neutral and anionic nucleophiles
(Oxford : Pergamon-Elsevier Science Ltd, 2010)
Vinyl bromides derived from 2-alkylidene-4-oxothiazolidines represent a class of vinyl halides, which readily undergo a bromophilic attack by a range of nucleophiles. With Ph(3)P, AcS(-), CN(-), I(-), F(-), Ac(2)CH(-) and ...
Steroid template associated peptides: design, synthesis and 2D NMR characterization of a novel protected 18-Phe,19-Gly-containing steroidal compound
(Oxford : Pergamon-Elsevier Science Ltd, 2007)
We report herein the synthesis of a novel modified steroid with two rigidly positioned amino acids in C- and N-protected forms (Gly-OtBu and N-Fmoc-l-Phe) at the angular positions (C-18 methylamino group and C-19 carboxylic ...
2-Alkylidene-4-oxothiazolidine S-oxides: synthesis and stereochemistry
(Oxford : Pergamon-Elsevier Science Ltd, 2013)
A series of 5-unsubstituted and 5-substituted 2-alkylidene-4-oxothiazolidine-S-oxides were synthesized by the sulfur-oxidation with m-CPBA. The stereochemistry of 5-substituted sulfoxides was determined by means of NMR ...
Unusual mode of reactivity of 2-alkylidene-4-oxothiazolidine S-oxides under the Pummerer reaction conditions
(Oxford : Pergamon-Elsevier Science Ltd, 2013)
The reactivity of 2-alkylidene-4-oxothiazolidine S-oxides under the Pummerer reaction conditions, using Ac2O, TFAA, SOCl2 and SOBr2 as initiators, has been examined. Almost all reactions proceeded with absolute regioselectivity ...
Structure, configuration, conformation and quantification of the push pull-effect of 2-alkylidene-4-thiazolidinones and 2-alkylidene-4,5-fused bicyclic thiazolidine derivatives
(Oxford : Pergamon-Elsevier Science Ltd, 2010)
Structures of a series of push-pull 2-alkylidene-4-thiazolidinones and 2-alkylidene-4,5-fused bicyclic thiazolidine derivatives were optimized at the B3LYP/6-31G(d) level of theory in the gas phase and discussed with respect ...