Lichtinduzierte Freisetzung von Riechstoffen. Synthesen und Untersuchungen von neuen fragcages.

In this work the photochemical behavior of volatile compounds was examined. In particular two kinds of caged compounds were synthesized and investigated. For these compounds the photochemical activity and the potential as properfumes were examined.

The first class of compound was aldol-cages. A series of aldol-photocages were synthesized via Mukaiyama reactions from various aldehydes and ketones in high syn-Selektivität.Photochemical analysis subsequent to the synthesis revealed that the aldol cages can be cleaved to the corresponding fragments under high quantum yields following a Norrish type II reaction. The photochemical fragmentation was realized by irradiation with solar light and with UV-Light. Furthermore, 1,5-diketone photocages were obtained from ketones and a,ß unsaturated ketones via Michael-addition. The following irradiations with solar-respectively UV-light, lead to decomposition of the photocages to the corresponding fragments. The absolute quantum yields of some of the 1,5-diketone-photocages were determined using transient spectroscopy. The results allowed a proposal for a mechanism for the photo-cleavage of the 1,5-diketone-photocages.