Details

Autor(en) / Beteiligte

• Barbosa, Luiz Cláudio de Almeida
• Teixeira, Robson Ricardo
• Nogueira, Leonardo Brandão
• Maltha, Celia Regina Alvares
• Doriguetto, Antônio Carlos
• Martins, Felipe Terra

Titel

A comparative study on the crystal structure of bicycle analogues to the natural phytotoxin helminthosporins

Ist Teil von

• Journal of molecular structure, 2016-02, Vol.1105, p.256-262

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2016

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Herein we described structural insights of a series of analogues to helminthosporin phytotoxins. The key reaction used to prepare the compounds corresponded to the [3 + 4] cycloaddition between the oxyallyl cation generated from 2,4-dibromopentan-3-one and different furans. Their structures were confirmed upon IR, NMR and X-ray diffraction analyses. While bicycles 7, 8 and 9 crystallize in the centrosymmetric monoclinic space group P21/c, compound 10 was solved in the noncentrosymmetric orthorhombic space group P212121. The solid materials obtained were shown to be racemic crystals (7, 8, 9) or racemic conglomerate (10). In all compounds, there is formation of a bicycle featured by fused tetrahydropyranone and 2,5-dihydrofuran rings. They adopt chair and envelope conformations, respectively. Crystal packing of all compounds is stabilized through C–H•••O contacts. Conformational aspects as well as similarities and differences among the crystal structures of the synthesized analogues are discussed. [Display omitted] •Compounds 7, 8 and 9 crystallize in the monoclinic system with P21/c space group.•Compound 10 crystallizes in the non-centrosymmetric monoclinic space group P212121.•Crystal packing of all compounds is stabilized through C–H … O contacts.•There is formation of a bicycle featured by fused tetrahydropyranone and 2,5-dihydrofuran rings.•The obtained solid materials are formed by racemic crystals (7-9) or racemic conglomerate (10).