Synthesis of novel 4-amidopyranonaphthoquinone derived from nor-lapachol by Prins-Ritter reaction

The multi-component one-pot synthesis has received great importance because of its wide range of applications in pharmaceutical chemistry for the production of structural scaffolds and combinatorial libraries for drug discovery. In this context, three component coupling (3CC) reactions have proven remarkably successful in generating molecular complexities in a single step operation. 1 The 4amidotetrahydropyran ring system is a core structure in a number of natural products 2 and generally, are prepared via Prins cyclization using acid catalysis. However, the use of Ritter amidation to terminate Prins cyclization is scarce, hence an efficient and practical methodology for the Prins-Ritter type reaction would be of great importance for the preparation of structurally diverse tetrahydropyran derivatives for the drug discovery process.