Naphtho-anellated [5.6.5]- and [6.5.5.5]fenestranes

Article abstract of DOI:10.1016/0040-4020(96)00788-0

The synthesis of several naphtho-anellated fenestrane derivatives 16 and 20-26 is described for the first time. Among these, a 'broken' dibenzo,(naphtho-d,e)[5.6.5]fenestrane, 9, and two isomeric benzo,di(naphtho-a)[6.5.5.5]fenestrane ketones, 23 and 24, were obtained in good yields by using the two-fold cyclodehydration route via the corresponding (spiro-) 1,3-indandiols. Attempts to prepare fenestranes that contain more than one six-membered ring failed.