Photocycloaddition Reactions of 5,5‐Dimethyl‐3‐(3‐methylbut‐3‐en‐1‐ynyl)cyclohex‐2‐en‐1‐one |
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| Authors: | Inga Inhülsen Jürgen Kopf Paul Margaretha |
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| Institution: | 1. Chemistry Department, University of Hamburg, Martin‐Luther‐King Platz 6, D‐20146 Hamburg, (phone: +4940428384316;2. fax: +4940428385592) |
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| Abstract: | The title cyclohexenone 1d undergoes photodimerization selectively at the exocyclic C?C bond to give a 1 : 1 mixture of 1,2‐dialkynyl‐1,2‐dimethylcyclobutanes 6 and 7 . On irradiation in the presence of 2,3‐dimethylbuta‐1,3‐diene, 1d affords bicyclo8.4.0]tetradeca‐1,2,3,7‐tetraen‐11‐one 9 . This – formal – (6+4)‐cycloadduct undergoes quantitative isomerization to 3‐cycloheptadienyl‐2,5,5‐trimethylcyclohex‐2‐enone 11 on treatment with basic silica gel. |
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| Keywords: | Cyclodeca‐1 2 3 7‐tetraenes Cyclohexenone photodimerization Photocycloaddition reactions X‐Ray crystallography Hexa‐1 5‐dien‐2‐ynes 1‐acyl‐ |
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