W. Reith

Identification and synthesis of the major sex pheromone of the olive fly (Dacus oleae)

The major component of the sex pheromone of the olive fly has been shown to be 1,7-dioxaspiro[5.5] undecane (1) and its structure has been confirmed by unambiguous synthesis; field studies have confirmed its biological activity.

Multicomponent Mandibular Gland Secretions in Three Species of Andrena Bees (Hym., Apoidea)

Abstract 50 volatile constituents of the mandibular gland secretions in males and females of three species of Andrena bees, A. wilkella (Chr.), A. ovatula (K .) and A. ocreata (K .), have been identified. The secretions are made up of a series of spiroacetals of four different systems together with mono-terpenes and unbranched acyclic compounds. Many of the components, particularly several of the dominant ones, occur in both sexes of all three species, so that the volatile secretions are qualitatively very similar. Females contain about 100 μg per individuum , which is 3-5 times the amount of the males’ secretions. Major spiroacetals are E,E- and Z ,E-2,8-dimethyl-1,7-dioxa-spiro[5.5]undecane and E,E-and Z,E-2-ethyl-7-methyl-1,6-dioxaspiro[4.5]undecane, while prominent monoterpenes are geraniol and citronellol. Straight chain hydrocarbons C17, C19, C21 and C23 occur in fairly large amounts, mostly with increasing concentrations. With respect to the quantitative distribution of components of minor concentration, the bouquet of A. wilkella is clearly distinguishable from A. ovatula and A. ocreata which from the morphological and ethological point of view are more closely related. Behaviour tests with A. wilkella indicate high biological activity of the main spiroacetal.

2,9-dioxabicyclo[4.2.1]Nonan - darstellung, massenspektroskopie und umlagerung eines neuen heterocyclischen systems

Abstract Nine different methyl-substituted compounds of a new acetal system 5 are synthesized from 4-(5-methyl-2-furyl)alkanoles 1 and are rearranged to ketones 6 ; mass spectroscopic fragmentation patterns are described.

Pheromone Bouquet of the Mandibular Glands in Andrena haemorrhoa F. (Hym., Apoidea)

Abstract The complex volatile secretion from the mandibular glands of Andrena haemorrhoa (Hym., Apoidea) has been analysed by GC/M S. It is composed primarily of three groups of compounds: 1. Spiroacetals of five different systems: two 1,6-dioxyspiro[4.4]nonanes, four 1,6-dioxaspiro[4.5] decanes, two 1,7-dioxaspiro[5.5]undecanes, one 1,6-dioxaspiro[4.6]undecane and one 1,7-dioxa-spiro[5.6]dodecane. 2. Straight chain fatty acid derivatives: methyl ketones, primary and secondary alcohols, acetates and hydrocarbons. 3. Isoprenoids: geraniol and geranyl acetate. Mass spectral fragmentation patterns have been studied for several synthesized spiroacetals.