The synthesis of bioactive sesqui- and diterpenoids is of continuing relevance. We present two distinct methodologies for the synthesis of polycyclic systems associated with such natural products. The Diels-Alder reaction of para-benzoquinones and their nitrogen derivatives, with simple dienes, leads to bi- and tricyclic products with structures which are ready for transformation into various groups of terpenoids, with predictable chemo-, regio- and stereoselectivity. On the other hand, the ring expansion of (R)-(-)-carvone into a chiral enantiopure cycloheptenone, followed by alkylations and ring closing metathesis, leads to the perhydroazulene system found in several sesqui- and diterpenoids. The experimental work is being linked to computer calculations, from simple conformational analysis of intermediates, to the determination of activation energies of the reactions. (AU)
Articles published in Agência FAPESP Newsletter about the research grant:
BROCKSOM, TIMOTHY JOHN;
DESIDERA, ANDRE LUIZ;
ALVES, LEANDRO DE CARVALHO;
DE OLIVEIRA, KLEBER THIAGO.
The New Directions of Organic Synthesis.
CURRENT ORGANIC SYNTHESIS,
Web of Science Citations: 6.