Unique reactivity of anti- and syn-acetoxypyranones en route to oxidopyrylium intermediates leading to a cascade process

Erica L Woodall; Justin A Simanis; Christopher G Hamaker; John R Goodell; T Andrew Mitchell

doi:10.1021/ol4012986

Unique reactivity of anti- and syn-acetoxypyranones en route to oxidopyrylium intermediates leading to a cascade process

Org Lett. 2013 Jul 5;15(13):3270-3. doi: 10.1021/ol4012986. Epub 2013 Jun 21.

Authors

Erica L Woodall¹, Justin A Simanis, Christopher G Hamaker, John R Goodell, T Andrew Mitchell

Affiliation

¹ Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, USA.

PMID: 23790080
DOI: 10.1021/ol4012986

Abstract

Unique reactivity of anti- and syn-acetoxypyranones was observed in oxidopyrylium-alkene [5 + 2] cycloadditions. The subtle interplay between the corresponding acetoxypyranone conformation and steric bulk of tertiary amine bases causes syn-acetoxypyranones to undergo [5 + 2] cycloaddition appreciably faster than anti-acetoxypyranones. Additionally, the efficiency of a cascade process that afforded a novel tetracyclic lactol was determined to be dependent on the relative stereochemistry of each diastereomer, the amine base utilized, and the addition of water.