U. Lindemann et al., Diastereoselective synthesis of 3-hydroxy-3-phenyl-cyclobutanoic derivatives by photocyclization, J PHOTOCH A, 119(2), 1998, pp. 73-83
Citations number
26
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
Irradiation of 2-substituted 4-oxo-4-phenyl-butanoic amide 1a and esters 1b
-f affords the corresponding cyclobutanols 4, 5 and 6. The diastereoselecti
vity of photocyclization depends on carboxyl and gamma-substituents. In the
case of pyrrolidide 10 products 13 and 14 which are formed via a competiti
ve epsilon-hydrogen transfer are obtained along with 2, 11 and 12 which are
the result of gamma-hydrogen abstraction. The relative configurations of t
he photoproducts 4-6 and 12-14 are established by NMR and X-ray analysis. (
C) 1998 Elsevier Science S.A. All rights reserved.