Improved Understanding of Conformational Preferences of Furanosides: Potential Energy Surface Scans of Permethylated Pentofuranosides

<p>The results of the computational methods show a greater stereocontrol at the 3-methoxy position than at the 2-methoxy position. The scans also show that both the 3-methoxy and 2-methoxy substituents prefer to be in the pseudoaxial position. These results do not differ greatly with formyl protecting groups except in the case of anchimeric assistance.</p> <p>The Woerpel group at the university of California’s experimental research proposed the rule of “inside attack”2 where the nucleophile attacks the cation on the inside of the preferred 3E conformation, but their results could only be verified completely if the second carbon’s protecting group was pseudoequatorial3. The computations deviate from this result.