Silicon in Synthesis: Synthesis of Necine Bases (±)- Macronecine and (±)-Supinidine and an Approach to Benzoisoquinoline Alkaloid (-)-Chrysanthone A: Over the past several years organosilicon chemistry has provided unique solutions for innumerable challenges in synthetic organic chemistry. Among all the silicon-based carbon nucleophiles now in use, allylsilanes occupy a premier place in terms their numerous applications in this arena. These species are endowed with highly nucleophilic π-systems and are yet stable towards a wide range of reagents and most of the common functional group manipulations, such as saponification, reduction, oxidation, etc. On the other hand, they can be readily activated by the so-called initiators (electrophiles), which are generated in situ by addition of Lewis acid. Besides allylation reaction of allylsilanes can also be carried out under nucleophilic conditions usually in the presence of a fluoride ion. In this laboratory, a comprehensive program was initiated a few years ago to develop new and efficient methods for the preparation of functionalized allylsilanes and demonstrate their utility in the synthesis of structurally intriguing and/or biologically significant natural products. The thesis entitled “Silicon in Synthesis: Synthesis of Necine Bases (±)-Macronecine and (±)- Supinidine and an Approach to Benzoisoquinoline Alkaloid (-)-Chrysanthone A” is an effort in this direction and is divided into two parts, part-I and part-II. Part-I is further subdivided into two sections.