Das, Bijay Ketan2024-03-272024-03-272022ROLL NO.166122030https://gyan.iitg.ac.in/handle/123456789/2568Supervisor: Punniyamurthy, TThe thesis is divided into four chapters. The first chapter describes the general introduction to the opening and cyclization of the strained ring system for the synthesis of six-membered heterocycles. The second chapter focuses on the synthesis of piperazines and tetrahydropyrazines through stereospecific ring-opening and cycloisomerization of aziridines with N-propargylamines. Third chapter covers stereospecific synthesis of substituted 1,4-oxazine via Zn/Ag Relay catalyzed ring opening/hydroalkoxylation of oxiranes with N-propargylamines. Chapter four deals with the stereospecific assembly of tetrahydroquinolines via tandem ring-opening/oxidative cyclization of donor-acceptor cyclopropanes with N-alkyl anilines.enThesis