A. Lipp, M. Selt, D. Ferenc
Feb 18, 2019
A fully regio- and diastereoselective electrochemical 4a-2'-coupling of a 3',4',5'-trioxygenated laudanosine derivative enables the synthesis of the corresponding morphinandienone. This key intermediate is further transformed into (-)-oxycodone through conjugate nucleophilic substitution for E-ring closure and [4 + 2] cycloaddition with photogenerated singlet oxygen to accomplish diastereoselective hydroxylation at C-14. The anodic transformation provides high yields and can be performed under constant current conditions both in a simple undivided cell or in continuous flow.