Institut de Chimie Moléculaire et des Matériaux d'Orsay

Laboratoire de Synthèse Organique et Méthodologie - LSOM

Cyclopropanes : Syntheses and Applications

The derivatives cyclopropanic constitute synthons basic very effective giving access natural very elaborate products or not. To date, the most effective method to reach the cyclopropanic entity is a reaction of addition in the presence of Titane (IV) of a Hard grindstone reagent on a molecule having a function such as ester, amide, nitrile, etc… This type of reaction known under the name of cyclopropanation of Kulinkovich can stéréosélectivement be made way inter or intramolecular and gives access functionalized cyclopropanes.

RECENT APPLICATIONS

One of the applications of the intramolecular reaction is the synthesis of oxygenated heterocycles making it possible to obtain with acceptable outputs of the oxacycles of various sizes which one finds for example in compounds allelopathic such as the héliannuols K and L isolated from the flowers of sunflower and presenting properties weedkillers.

1. Synthesis of oxacycles

2. Chimio and Stereoselectivity

The reaction of Kulinkovich applied to certain Hard grindstone cyclic results in the formation of cyclopropanols bicyclic. The sulphonates resulting from such vinylcyclopropanols can undergo pallado-catalysed substitutions being able to lead to products of reaction preserving the integrity of cyclopropane or to lead to products of opening of cycle.

3. Projects under development: Extension towards the amino acids

Peptides made up of a sequence of amino acids are the subject of many research because they are implied in or the infection mechanisms of defence of the living organisms (enzymes, parasites, virus, etc…). The incorporation of new amino acids in a peptide chain will modify the biological properties of protein and will possibly lead to new physiological activities.
Many types of amino acids are accessible by our methodology and our work continues in this field.