Olefin metathesis offers an attractive possibility to carry out CC bond formation with non-activated double bonds? Especially interesting are selective ring closing reactions in the presence of other fimctionalities. In the course of our efforts to apply oletin metathesis to natural product synthesis, we became interested in seven membered ring cychzations to obtain hydroazulenes. Starting from 1,3-cyclopentanedione derivatives I, different hydroazulene ...
