4 results match your criteria variety oxazolidin-2-ones

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Stereoselective Synthesis of Highly Substituted Tetrahydropyrans through an Evans Aldol-Prins Strategy.

J Org Chem 2018 08 6;83(16):9039-9066. Epub 2018 Aug 6.

Instituto Universitario de Bio-Orgánica "Antonio González" (IUBO-AG), Centro de Investigaciones Biomédicas de Canarias (CIBICAN), Departamento de Química Orgánica , Universidad de La Laguna (ULL) , Avda. Astrofísico Francisco Sánchez 2 , 38206 San Cristóbal de La Laguna , Tenerife , Spain.

A direct and general method for the synthesis of naturally occurring 2,3,4,5,6-pentasubstituted tetrahydropyrans has been developed, employing β,γ-unsaturated N-acyl oxazolidin-2-ones as key starting materials. The combination of the Evans aldol addition and the Prins cyclization allowed the diastereoselective and efficient generation of the desired oxacycles in two fashions: a one-pot Evans aldol-Prins protocol, in which five new σ bonds and five contiguous stereocenters were straightforwardly generated, and a two-step version, which additionally permitted the isolation of β,γ-unsaturated alcohol precursors bearing an N-acyl oxazolidin-2-one in the α position. From these alcohols were also obtained halogenated pentasubstituted tetrahydropyrans as well as 2,3,4,5-tetrasubstituted tetrahydrofurans, shedding light on the mechanism of the process. Read More

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Activation of aldehydes by exocyclic iridium(i)-η:π-diene complexes derived from 1,3-oxazolidin-2-ones.

Dalton Trans 2016 Nov 29;45(42):16878-16888. Epub 2016 Sep 29.

Área Académica de Química, Universidad Autónoma del Estado de Hidalgo, Carretera Pachuca-Tulancingo Km. 4.5, Mineral de la Reforma, Hidalgo 42090, México.

The Ir(i) complexes [TpIr(η-1,4-diene)] 2b and 2c react thermally with a variety of aromatic aldehydes, 3a-e, to generate the metallabicyclic compounds 4e-k and the Fischer-type carbenes 5a-b in moderate yields. These reactions are proposed to take place with the initial formation of η-aldehyde adducts as key intermediates. The formation of the metallabicyclic compounds 4e-k involves a formal decarboxylation process at the exo-2-oxazolidinone diene and an ortho metallation of the aromatic ring. Read More

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November 2016

Weak C-H···O and C-H···π hydrogen bonds and π-π stacking interactions in a series of four N'-[(E)-(aryl)methylidene]-N-methyl-2-oxo-1,3-oxazolidine-4-carbohydrazides.

Acta Crystallogr C Struct Chem 2015 Aug 7;71(Pt 8):647-52. Epub 2015 Jul 7.

Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland.

Oxazolidin-2-ones are widely used as protective groups for 1,2-amino alcohols and chiral derivatives are employed as chiral auxiliaries. The crystal structures of four differently substituted oxazolidinecarbohydrazides, namely N'-[(E)-benzylidene]-N-methyl-2-oxo-1,3-oxazolidine-4-carbohydrazide, C12H12N3O3, (I), N'-[(E)-2-chlorobenzylidene]-N-methyl-2-oxo-1,3-oxazolidine-4-carbohydrazide, C12H12ClN3O3, (II), (4S)-N'-[(E)-4-chlorobenzylidene]-N-methyl-2-oxo-1,3-oxazolidine-4-carbohydrazide, C12H12ClN3O3, (III), and (4S)-N'-[(E)-2,6-dichlorobenzylidene]-N,3-dimethyl-2-oxo-1,3-oxazolidine-4-carbohydrazide, C13H13Cl2N3O3, (IV), show that an unexpected mild-condition racemization from the chiral starting materials has occurred in (I) and (II). In the extended structures, the centrosymmetric phases, which each crystallize with two molecules (A and B) in the asymmetric unit, form A+B dimers linked by pairs of N-H···O hydrogen bonds, albeit with different O-atom acceptors. Read More

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Modified Mg : Al hydrotalcite in the synthesis of oxazolidin-2-ones.

Org Biomol Chem 2005 Mar 10;3(6):967-9. Epub 2005 Feb 10.

Department of Organic Chemical Technology, Budapest University of Technology and Economics, H-1521, Budapest, Hungary.

The modified Mg : Al (3 : 1) hydrotalcite has been found to be an efficient catalyst in the conversion of carbamates into oxazolidin-2-ones under mild reaction conditions. A wide variety of oxazolidin-2-ones were obtained with excellent chemical yield. Read More

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