Intramolecular oxymercuration of stereoisomeric cyclohexyl-belted poly(spirotetrahydrofuranyl) platforms

Leo A. Paquette, David G. Bolin, Marshall Stepanian, Bruce M. Branan, Uppuluri V. Mallavadhani, Jinsung Tae, Shawn W.E. Eisenberg, Robin D. Rogers

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

The four tetraspiro carbinols 28, 30, 41, and 43 and the three trispiro cyclohexenones 25, 38, and 53 have been synthesized and individually subjected to intramolecular oxymercuration. The three-dimensional structures of all 10 products have been unequivocally established by X-ray crystallographic analysis. In seven of these structures, the preferred solid- state conformation features an axially disposed C-Hg bond where the mercury atom is internally chelated in. a 1,3-diaxial relationship to at least one or, more often, two oxygen centers. An unusually strong preference has been observed for equatorial occupancy on the part of the C-O bonds. This bias can be attributed to the relief of torsional strain effects that arise when gauche CH2- - -CH2 interactions are skirted. An important mechanistic distinction separates the kinetically preferred trans mercuricyclization of the tetraspiro alcohols from the contrasting cis stereochemical ring closure exhibited predominantly by the unsaturated ketones. In the first instance, the approach of Hg2+ to the double bond is governed to a large extent by coordination to a proximal axially oriented ether oxygen. Where the ketones are concerned, precoordination to the Lewis basic carbonyl oxygen presumably initiates spirocyclization in a fashion controlled by the conformational preference of the resident tetrahydrofuranyl subunits.

Original languageEnglish
Pages (from-to)11603-11615
Number of pages13
JournalJournal of the American Chemical Society
Volume120
Issue number45
DOIs
Publication statusPublished - 1998 Nov 18

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Cite this

Paquette, L. A., Bolin, D. G., Stepanian, M., Branan, B. M., Mallavadhani, U. V., Tae, J., Eisenberg, S. W. E., & Rogers, R. D. (1998). Intramolecular oxymercuration of stereoisomeric cyclohexyl-belted poly(spirotetrahydrofuranyl) platforms. Journal of the American Chemical Society, 120(45), 11603-11615. https://doi.org/10.1021/ja981756p