2-Lower alkyl-cyclopentan-1,3-diones are important intermediates for the total synthesis of steroids. A number of syntheses of this important class of intermediates have been reported, including syntheses which involve the cyclization of gamma-ketoesters in the presence of base. In particular, U.S. Pat. No. 3,349,130 to Bucourt, et al., teaches such cyclization in the presence of alkali metal tertiary alcoholates. French Pat. No. 1,564,830 to Watson, et al. teaches such cyclizations in the presence of sodium hydride.
Since alkali metal tertiary alcoholates and sodium hydride are relatively expensive and somewhat difficult to prepare in large quantities and are thus not practical for a large-scale commercial cyclization process, it would be desirable to have a cyclization method which would afford high yields of product and which would utilize relatively inexpensive and easy to prepare cyclization agents.