Notizen: Photodimerisierung von 6-trans-Styryl-4- methoxy-2-pyr on ( = 5.6-Dehydrokawain) und cis-Isomerisierung von ( ± )-Kawain/ Photodimerisation of 6 -1 rans-Styry 1 - 4 - methoxy- 2 - pyrone ( = 5,6-Dehydrokawain) and cis-Isomerisation of (±)-Kawain

Abstract

<jats:title>Abstract</jats:title><jats:p> The photochemical transformation of 5,6-Dehydrokawain (1) to rel-(lR,6S,7S,8S)-5-methoxy-7-phenyl-8-[6-(4-methoxy-2-pyronyl)]-1-(E)-styryl-2-oxabicyclo[4,2,0]octa-4-en-3-one (2) by irradiation with a light bulb [1] is con-firmed. Kawain (3) turns out to be resistent to photochemical reaction in several tests. During irradiation by a Hg-lamp a transformation to cis-Kawain (4) takes place, however.</jats:p>