A stereoselective synthetic entry point to the 5−8− 5 carbocyclic core of the ophiobolins was developed. This strategy exploits the chiral tertiary alcohol of ophiobolin A to guide assmebly of the 5−8−5 scaffold in a single step via a photoinitiated cycloisomerization. Mechanistic insights into the origin of stereocontrol in this reaction are described, as are efforts to elaborate the resultant fused 5−8−5 ring system to the pharmacophore of ophiobolin A.

A concise, modular, and stereoselective synthetic entry point to the 5-8-5 carbocyclic core of the ophiobolins is described. This strategy exploits the chiral tertiary alcohol of ophiobolin A to guide assmebly of the 5-8-5 scaffold in a single step via photoinitiated isomerization. Mechanistic insights into the origin of stereocontrol in this reaction are described, as are efforts to elaborate the resultant 5-8-5 polycycle to the pharmacophore of ophiobolin A.

We report a method for direct enantioselective alkylation of 3‐alkynoic and 2,3‐alkendioic acids that form quaternary stereogenic centers, and application of this method to the total enantioselective synthesis of a complex alkaloid (+)‐goniomitine. The methods were effective in the alkylation of both 3‐alkynoic acids, 2,3‐alkendioic acids substrates with a broad range of heterocyclic and functionalized alkyl group substituents. Accompanying crystallographic studies provide mechanistic insight into the structure of well‐defined chiral aggregates, highlighting cation‐π interactions between lithium and alkyne groups.

We report a method for direct enantioselective alkylation of 3‐alkynoic and 2,3‐alkendioic acids that form quaternary stereogenic centers, and application of this method to the total enantioselective synthesis of a complex alkaloid (+)‐goniomitine. The methods were effective in the alkylation of both 3‐alkynoic acids, 2,3‐alkendioic acids substrates with a broad range of heterocyclic and functionalized alkyl group substituents. Accompanying crystallographic studies provide mechanistic insight into the structure of well‐defined chiral aggregates, highlighting cation‐π interactions between lithium and alkyne groups.