Asymmetric synthesis of the core structure of the melodinus alkaloids

Article abstract of DOI:10.1016/S0040-4039(98)02510-6

The strategy developed for an asymmetric synthesis of (+)-meloscine (1) features an early incorporation of the aromatic ring in 1 as the 5-benzyl substituent in 2. The highly diastereoselective Birch reduction-alkylation 2 → 3, the unraveling of 3 to the butyrolactone carboxylic acid 7, and the Mannich cyclization 9c → 10c are the key steps in the synthesis of the core tricyclic unit in 1.