Antifertility Agents: A Synthetic Entry to Yuehchukene Analogues; Stereoselective Synthesis of 7,7-Bis-nor-yuehchukene via 9-Methyl-6-oxo-6aβ-7,8,10aβ-tetrahydroindenoindole
Intermolecular Diels-Alder reaction and polyphosphate ester-catalysed intramolecular acylation are used in a synthetic approach to 9-methyl-6-oxo-6aβ-7,8,10aβ-tetrahydroindenolindole (15),the basic structure of the antifertility agent yuehchukene (