Application of hydroformylation for the stereoselective synthesis of piperidine alkaloids

Abstract

This thesis describes the advantages of hydroformylation, when incorporated into natural product synthesis as well as, flow chemistry. The first chapter gives a brief overview of application of hydroformylation in natural product synthesis. It highlights the importance of hydroformylation as a tool for formation of a new carbon-carbon bond and its capability of introducing reactive aldehyde functional groups. The second and third chapters describe the synthesis of pseudoconhydrine and azimic acid using a common methodology that incorporates hydroformylation, for a simple yet efficient stereoselective synthesis of these types of piperidine alkaloids. The fourth chapter explores the advantages of application of hydroformylation in flow chemistry. It discusses the improvement in the safety profile, the simplification in the experimental procedures and the efficient synthesis of styrenes as compared to batch chemistry. The fifth chapter explores the possibilities of inducing a 1,2-alkyl shift in 2,3,6-trisubstituted piperidines.

Accelerated Canine Retraction by Corticotomy Assisted or Periodontal Distraction

“…Several techniques of rapid canine retraction can be used as alveolar surgery and distraction osteogenesis (17) which accelerates the bone resorption, and osteoclast activity (35) . Also, because surgical injury to alveolar bone such as corticotomy and MOPs can induce local inflammatory reaction, chemokine and cytokine levels are elevated, hence osteoclast stimulation and tooth movement acceleration (1,36) . However, these techniques involve invasive flap surgery; so, a novel simplified flapless approach was performed to accelerate the rate of canine movement by periodontal ligament distraction which was reported as technique not resulted in damage to the periodontal ligament, nor affected pulp vitality (37) .…”