An Ir/Brønsted acid dual-catalyzed asymmetric cascade reaction of 2-(1-hydroxyallyl)phenols with isochroman ketals was developed, affording antifungal spiroketals with high enantioselectivities.
In this review, we examine the origins and synthesis of bioactive spiroketal-containing natural products isolated from traditional Chinese medicines.
Metal-free, electrochemical synthesis of spiroketals is presented, using anodic oxidation of malonic acids under mild conditions. This sustainable approach enables access to diverse spiroketal frameworks with potential for flow adaptation.
An electrophilic dearomatizative thiocyanation/spirocyclization of benzofurans with N-thiocyanatosuccinimide has been accomplished by Lewis acid catalysis with CuOTf under mild conditions.
α-Keto ketals and benzannulated oxo-spiroketals have been regioselectively synthesized using a Sc3+-coordinated riboflavin tetraacetate photocatalyst with electron-deficient alkynes and alkynediols, respectively.