Oxidative Additions with 1,4-Dihydropyridines: A One-Pot Synthesis of 3,4,4a,5,8,8a-Hexahydro-2H-pyrido[3,2-b][1,4]oxazine Derivatives

Abstract

3,4,4a,5,8,8a-Hexahydro-2H-pyrido[3,2-b][1,4]oxazine derivatives (2a–h) are conveniently prepared in excellent yields by a one-pot synthesis from 1,4-dihydropyridines. The key transformation features an electrophilic interaction of iodine with N-alkyl-1,4-dihydropyridine (1a–d) in the presence of a nucleophile diethanol amine or N-methylethanol amine, stereoselectively leading to the corresponding bicyclic heterocycles (2a–h).

Graphical Abstract

Keywords:

• Dihydropyridine
• [1,4]-oxazines
• pyridooxazine
• tetrahydropyridine

ACKNOWLEDGMENT

We thank the University Grant Commission (UGC), New Delhi, for financial support.