p. 7123 - 7126
(1996)p. 1843 - 1846
(2002)3,3,6,6-tetramethylbicyclo[3.1.0]hexane-2,4-dione
2,2,5,5-tetramethylcyclohexa-1,3-dione
isopropylidenediphenylsulfurane
toluene-4-sulfonic acid 5,5-dimethyl-4-oxocyclopent-2-enyl ester
4-exo-hydroxy-3,3,6,6-tetramethylbicyclo[3.1.0]hexan-2-one