This monograph is a condensed form of the fundamental knowledge on the named reaction Prins cyclization in organic synthesis. This monograph consists of three distinct chapters: chapter 1 provides detailed description of the Prins cyclization, contemporary approaches to the synthesis of chiral 1,3-diol units and application to the total synthesis of biologically active natural products; chapter 2 describes the historical and biological background of the naturally occurring, cytotoxic 14-membered macrolide (+)-Neopeltolide, including their isolations, structural elucidation and previous synthetic approaches and my synthetic route to the total synthesis of (+)-Neopeltolide macrolactone, while chapter 3 provides information on the use of Prins cyclization for the synthesis of 4-iodo, 4-amido, 4-azidotetrahydropyran derivatives. This monograph is an indispensable reference for any chemist working with tetrahydropyran, dihydropyran and piperidine containing natural products.