Use of temporary tethers in the intramolecular [2+2] photocycloaddition reactions of tetrahydrophthalimide derivatives: a new approach to complex tricyclic lactones


Gulten Ş. , Sharpe A., Baker J. R. , Booker-Milburn K. I.

TETRAHEDRON, vol.63, no.18, pp.3659-3671, 2007 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 63 Issue: 18
  • Publication Date: 2007
  • Doi Number: 10.1016/j.tet.2007.02.064
  • Title of Journal : TETRAHEDRON
  • Page Numbers: pp.3659-3671

Abstract

The intramolecular [2+2] photocycloaddition reactions of a series of alkenols tethered to ethanolamine, L-(+)-valinol and R-(-)-2-phenylglycinol derived 3,4,5,6-tetrahydrophthalimides via a carbonate or silicon linkage have been examined. These [2+2] photocycloadditions gave the corresponding cyclobutanes in high yield with complete endo control in all cases and with diastereoselectivities as high as 8:1 with the chiral tethers. The cleavage of the temporary tethers by either desilylation or hydrolysis provided the endo diols. Cleavage of the ethanolamine linkage by reduction/hydrolysis precipitated an acid-catalysed fragmentation/ring expansion sequence to generate complex tricyclic lactones. (C) 2007 Elsevier Ltd. All rights reserved.