A new method for the aldol condensation of citral with butanone is described by which the condensation takes place mainly at the methylenc group of the ketone. The mechanism of the reaction is discussed.The condensation of an aldehyde with butanone may take place theoretically in two different ways, i.e. at the methylene group ( I ) or at the methyl 'group (11) of bhe ketone.The literature data show that the ratio between the amounts of the two compounds present in the condensation product is influenced by several factors.Harries and Miifler 3 ) demonstrated the influence of the catalyst; the condensation of benzaldehyde with butanone takes place practically exclusively at the methylene group when the mixture is saturated with hydrogen chloride.Whereas all available literature data 4 ) 6 ) seem to indicate that the I ) The method described in this gaper is the subject of patent applications (e.8.2 ) This paper was presented before the VIIIth Congress0 nazlonale di chimica.

A series of new indane derivatives with musk odour is described).

A n d e r of simple &nzene derivatives with mu& odour are described.In a recent paper * a series af new indane derivatives with a musk odour was described. In this series the compound with the strongest musk odour was found to be 4acetyl-lf1-dimethyl-6-t~butylindane (I). +It seemed interestinq to investigate whether 6he non-aromatic ring in the indane system is a requirement for the musk odour or ~h e t h e r it only serves as a convenient camier for some of the essential substituents. The latter was found to be the case: 3,5idi-t-butylacetophenone (11; white crystals: melting point: 38.639.0 a), a lower homolague of I in wlhich the nonaromatic ring h-as been opened while the * The compounds described in this paper are the subject of patent appli-

By reacting a-methylstyrene with formaldehyde in the presence of catalytic amounts of mineral acid, 4-methyl4-phenyl-m-dioxan is obtained in high yield. A t higher acid concentrations and in the presence of a large excess of formaldehyde, however, a series of secondary reactions occur, all characterized by the formation of a double 'bond followed by further condensation with formaldehyde and, where possible, cyclization by formation of rn-dioxan or tetrahydropyran rings. These reactions have been studied, a number of reaction products have been isolated and their structures have been established.Also in the case of styrene an extremely slaw secondary reaction of the same type could be realized and its products have been studied. The mechanism of these reactions is discussed. ,

The add-catalyzed reaction of dnnamyl alcohol with formaldehyde has ken studied. Prom the complex reaction product two m-dioxane derivatives and a triol have been isokted, and their structures have been studied.In a number of recent papers 1) we have described our work on the acid-cataIyzed reaction of formaldehyde with unsaturated compounds possessing a conjugated system of double bonds and an aromatic nucleus.It seemed interesting to study the course of this reaction when reactive groups which do not extend the conjugation *) are introduced into such compounds. since they may cause, by interaction with the normal reaction, the formation of unexpected reaction products and thus open up new synthetic routes.Among compounds of this type, cinnamyl alcohol is particularly interesting, since we may expect its reactivity towards formaldehyde to be of the same order as that of styrene, while its structure seems to be genetically related to the reaction of styrene with formaldehyde (1-111) I However, the reaction I11 can never be realized, because the carbonium ion I1 under any practical conditions is instantaneously