The synthesis of pseudopyronine B (2)
started with ester and progressed to pyrone in similar
fashion. Deacylation of by heating at 90 C in 90% H2SO4
yielded 6-heptyl-4-hydroxy-2-pyrone (9) with subsequent
acylation by hexanoyl chloride in TFA affording the pyrone
skeleton with the appropriate length carbon chain at C-3.