The thesis entitled "Synthesis of Sphingolipids, Azasugars and N-Heterocyclic Compounds-their Bio-evaluatuin" has been divided into two parts, Part A and Part B, each part is further divided into two Chapters. PART A: Chapter 1 deals with the importance of Sphingolipids and summarizes some of the important approaches towards these bioactive molecules and stereoselective synthesis of desired D-ribo-Phytosphingosine, D-erythro-Sphingosine and Sphinganine from D- Mannitol. Chapter 2 deals with the importance of azsugars and summarizes some of the important approaches towards these bioactive azasugars and stereoselective syntheses of desired 1-Deoxynojirimycin, D-Glucono- -lactam and D-Altrono- -lactam from D-Mannitol. PART B: Chapter 3 dealt with the introduction to Baylis-Hillman reaction and their applications and describes the syntheses of 2-pyridones and aminonicotinates. Chapter 4 dealt with the introduction to 1,4-Dihydro pyridines (1,4-DHPs) summarizes some of the earlier methods to 1,4-DHPs syntheses and describes the syntheses of 4-(2-chloropyridyl)-1,4-dihydropyridines derivatives and their evaluation of antituberculosis activity."