Synthesis of benzannulated spiroketals with gold-catalyzed cycloisomerization/spiroketalization cascade†
Abstract
An unprecedented gold-catalyzed intramolecular cycloisomerization of alkynyl alcohol and intermolecular spiroketalization reaction with quinone monoimines has been successfully developed. By using this novel gold-catalyzed cascade, a variety of 5,5-benzannulated spiroketals were obtained from easily available starting materials under mild conditions.