Photocyclodimers of ‘Made‐to‐Measure’ Seven‐ and Six‐Membered Cyclic Enones |
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| Authors: | Kerstin Schmidt Paul Margaretha |
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| Institution: | 1. Department of Chemistry, University of Hamburg, Martin‐Luther‐King Platz 6, D‐20146 Hamburg, (phone: +49‐40‐428384316;2. fax: +49‐40‐428385592) |
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| Abstract: | On irradiation (350 nm) in benzene as solvent, dioxepinone 6 and benzoxepinone 7 afford quantitatively mixtures of two diastereoisomeric head‐to‐head dimers, respectively. In both cases, on contact with SiO2 the minor dimer containing trans‐ring fusions undergoes spontaneous isomerization to the (major) cis‐transoid‐cis diastereoisomer. In contrast, thiopyranone 8 is converted selectively, but in very low yield, to dimer 13 . |
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| Keywords: | Photocyclodimerization Enones cyclic Oxepinones |
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