Synthetic approaches to five- and six-membered-ring systems are
commonly undertaken through cyclization and cycloaddition reactions,
but the formation of seven- and eight-membered-ring systems are
not as abundant. An efficient and high-yielding method for the synthesis
of seven- and eight-membered-ring nitrogen-containing heterocycles
by ring-closing metathesis is reported.
uracil - azepine - azocine - ring-closing
metathesis
