Stereoselective β‐C‐Glycosylation by a Palladium‐Catalyzed Decarboxylative Allylation: Formal Synthesis of Aspergillide A

Abstract

Mild and sweet: The title reaction proceeds under mild conditions with high regio‐ and diastereoselectivity (see scheme, PG=protecting group, DiPPF=1,1′‐bis(diisopropylphosphino)ferrocene). This reaction is suitable for a wide range of glycal‐derived γ‐ketone esters and affords C‐glycosides with exclusive β‐selectivity. The method was further applied to a concise formal synthesis of aspergillide A.

β‐Type Glycosidic Bond Formation by Palladium‐Catalyzed Decarboxylative Allylation

“…Metal‐catalyzed decarboxylative allylation, with the effort of many pioneers such as Tunge,8 Trost,9 and Stoltz,10 has proven its synthetic utility in organic chemistry in general 11. Recently, we have developed a palladium‐catalyzed decarboxylative β‐ C ‐glycosylation by employing this strategy 12. As a continuation of our efforts in discovering new glycosylation methods,13 We present herein a palladium‐catalyzed decarboxylative allylation approach to the synthesis of various β‐ O ‐glycosides, including oligosaccharides, from glycal carbonates (Scheme , d).…”

Applications of Wittig Reaction in the Total Synthesis of Natural Macrolides

“…PSU-MA119 by Rukachaisirikul and co-workers. [166] Structurally, pestalotioprolide A 126 is an (E)-α,β-unsaturated macrolactone bearing four contiguous hydroxyl groups and a (Z)-double bond, hence a dihydroxy analog of seiricuprolide. Tadpetch and co-workers in 2015 reported a chiron method for the formation of the suggested structure of pestalotioprolide A 126starting from D-(+)-gluconic acid δ-lactone.…”

Glycosylation via Transition‐Metal Catalysis: Challenges and Opportunities

“…In addition, Liu and co‐workers developed a palladium‐catalyzed decarboxylative allylation using glycals bearing C3‐β‐keto esters for the stereoselective synthesis of β‐ C ‐glycosides . As shown in Table , in the presence of 5 mol‐% Pd(OAc) 2 and 10 mol‐% 1,1′‐bis(diisopropylphosphino)ferrocene (D i PPF), heating glycals bearing C3‐β‐keto esters 217 in toluene at 60 °C for 2 h afforded desired β‐ C ‐glycosides 218–223 in good to excellent yields and excellent anomeric selectivity.…”