Journal de la Société Chimique de Tunisie, 2007, 9, 17-22 17 T. Turki et al. A TOTAL SYNTHESIS OF (E)-11-HYDROXYUNDEC-2-ENOIC ACID, A NEW HOMOLOGOUS ROYAL JELLY ACID T. Turki, S. Khamri, H. Amri * Laboratoire de Chimie Organique et Organométallique, Faculté des Sciences de Tunis, Campus Universitaire, 2092 Tunis, Tunisie (Reçu le 14 Janvier 2007, accepté le 11 Mai 2007) * corresponding author, e-mail: hassen.amri@fst.rnu.tn ; tel: +216 71 872600 ; fax: +216 71 885008 ABSTRACT : A total synthesis of (E)-11-hydroxyundec-2-enoic acid 10, an homologous of royal jelly acid and queen substance of honey bee was performed using commercially available nonan-1,9-diol. The general strategy including some key steps was based on the Wittig-Horner reaction of triethyl phosphonate in water in the presence of potassium carbonate on the protected 9-hydroxynonanal. Key words: Wittig-Horner reaction ; (E)-11-Hydroxyundec-2-enoïc acid ; royal jelly ; honey bee. In conjunction with our continuing interest in the application of the Wittig-Horner reaction 1-4 we describe here a total synthesis of (E)-11-hydroxyundec-2-enoic acid 10, an analogous component of royal jelly acid 5 2 and a bee pheromone 3. The reaction was performed under mild conditions, using liquid-liquid media and aqueous potassium carbonate as the base in the absence of phase transfer catalyst. (Scheme 1) CH 2 -A (EtO) 2 P O A = COOR, COR, CN Scheme 1 1 R-CHO + HO 3 COOH 6 COOH 5 O 2 Queen’s substance 3 is secreted by the queen honey bee, whereas royal jelly acid 2 is produced by the common honey bee and inhibits ovary developments in the worker bees and queen rearing within the colony 6 . Because of their biological importance, different synthetic strategies toward the synthesis of this class of compounds have been reported. All the proposed approaches require the use of expensive reagents and lengthy strategies 7,8 . The use of the Wittig-Horner reaction offers many advantages as it reduces the sequence length whilst avoiding the use of high cost protecting groups and the difficult separations which reduce the overall yield. In these conditions, the phosphonate 1 (A=COOR) mentioned above reacts with simple aldehydes and give rise exclusively to (E)-functional alkenes 9 with a total absence of side products.