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Photocycloaddition of Conjugated Cyclohex-2-enones to 2,3-Dimethylbuta-1,3-diene

✍ Scribed by Inga Inhülsen; Kerstin Schmidt; Paul Margaretha

Publisher
John Wiley and Sons
Year
2010
Tongue
German
Weight
149 KB
Volume
93
Category
Article
ISSN
0018-019X

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✦ Synopsis

Abstract

On irradiation, in the presence of 2,3‐dimethylbuta‐1,3‐diene, naphthalen‐2‐ones 1 are quantitatively and regioselectively converted to mixtures of diastereoisomeric cyclobutane adducts 3 and 4, whereas, under these conditions, 3‐(alk‐1‐ynyl)cyclohex‐2‐enones 5 give only one cyclobutane adduct 6 regio‐ and diastereoselectively. In contrast, 3‐(alk‐1‐ynyl)‐2‐methylcyclohex‐2‐enones 10 undergo [2+2]‐cycloaddition to the same diene exclusively at the C≡C bond to afford hitherto unknown 3‐cyclobutenylcyclohex‐2‐enones 11.

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