Degradation of triterpenic compounds from olive-pressing residues. Synthesis of trans-decalin type chiral synthons

Three seco-C-ring triterpenic compounds were obtained from oleanolic or maslinic acids from olive-mill solid wastes by photochemical and chemical reactions. From these oleantriene compounds, different remarkable sesquiterpene and nor-sesquiterpene fragments such as 3β-hydroxydrimenol (13) and epoxydecalone (16) were achieved through oxidative cleavages of the double bonds in the opened C-ring.