Collect. Czech. Chem. Commun. 1993, 58, 925-935

Intramolecular Cyclization of Steroidal Diketo Aldehydes to Acetals

Zbigniew Boncza-Tomaszewskia and Helmuth Duddeckb

a Department of Chemistry, Warsaw University, ul. Pasteura 1, 02-093 Warszawa, Poland
b Ruhr-Universitat, Fakultät für Chemie, Postfach 102148, D-4630 Bochum 1, Germany


As an attempt to prepare diketo aldehydes I and II conjugated ketones III and IV were converted to the respective keto diols V and VI, which were treated with periodic acid and independently with lead tetraacetate. However, instead of desired diketo aldehydes I and II, unexpected and interesting cyclized acetals X, XI, and XII were obtained. The structures and some of their chemistry are described in this paper.