Preussomerins G and I (2 and 3) have been synthesized for the first time. T
he key reaction in the synthesis is a possibly biomimetic tautomerization r
eaction depicted in Scheme 3 and the foregoing graphic. The driving force f
or this interesting rearrangement is primarily derived from the increase in
resonance energy associated with converting a naphthalene ring into two is
olated benzene rings.