Irradiation of a series of 3-alkoxypyridinium tetrafluoroborate salts in al
cohol solution resulted in the formation of cyclopentenone ketals by diaste
reoselective incorporation of the alcohol solvent under the basic condition
s of the photolysis reaction. In a second series of photochemical reactions
, the same 3-alkoxypyridinium salts were irradiated in water to yield beta-
hydroxycyclopentanones stereoselectively. (C) 1999 Elsevier Science Ltd. Al
l rights reserved.