PROCEDE POUR LA PREPARATION DE LA 29- HYDROXY-3,11-DIMETHYL-2-NONACOSANONE

LA PRESENTE INVENTION EST RELATIVE A UN NOUVEAU PROCEDE POUR LA PREPARATION DE LA 29-HYDROXY-3,11-DIMETHYL-2-NONACOSANONE DE FORMULE GENERALE(I) CI-APRES:(CF DESSIN DANS BOPI)ON OBTIENT LE PRODUIT (1) EN FAISANT REAGIR UN 2,10-DIMETHYL-28-OCTACOSANOATE D'ALCOYLE AVEC UN TRIALCOYLSILYLMETHYL LITHIUM POUR OBTENIR UN INTERMEDIAIRE DE FORMULE GENERALE (III) CI-APRES:(CF DESSIN DANS BOPI)PUIS EN TRAITANT CE PRODUIT INTERMEDIAIRE AVEC UN ACIDE.APPLICATION EN TANT QUE PHEROMONES. The compound of the formula /I/ is prepared by a./ reacting an alkyl /2,10-dimethyl-28-octacosanoate/ of the formula /II/, wherein R represents a C1-5 alkyl group and Y stands for a tetrahydropyranyl or a 2-ethoxyethyl group, with a trialkylsilylmethyl lithium in an ether-type solvent, reacting the thus-obtained intermediate of the general formula /III/, wherein R1, R2 and R3 each represent a C1-4 alkyl group with an aliphatic alcohol, treating the compound of the general formula /IV/ thus obtained, wherein Y is as defined above, with an acid; or b./ reacting an alkyl /2,10-dimethyl-28-octacosanoate/ of the general formula /II/ with a solution of methylsulfinylmethyde in dimethylsulfoxide in an ether-type solvent, treating the compound thus obtained with a reducing agent, e.g. aluminium amalgam, treating the thus-obtained compound of the general formula /IV/ with an acid, and separating the compound of the formula /I/ thus obtained from the reaction mixture. The compound of the formula /I/ produces a strong stimulating reaction on male German cockroach /Blattella Germanica/. Compounds of formula (II) are novel.