This monograph describes introduction of Prins cyclisation, previous approaches to the versatile intermediate 1,3 diols and its application in the synthesis of polyketide natural products. Scope of the prins cyclisation in the synthesis of multisubstituted tetrahydropyrans from aldehydes and homo allylic alcohols, is expanded. A new approach for the stereoselective synthesis of polyketide precursors containing 1,3-diol units, flanked by divergent alkyl branches with different functional groups. Using this 1,3 diol strategy synthesized biologically active molecule Crocacin C (antifungal and highly cytotoxic metabolite), Basiliskamide A & B (showed the antifungal activity against Candida albicans and Aspergillus fumigates). This monograph is unique with dealing with synthetic protocols for above natural products utilizing Prins cyclisation and 1,3 diol strategy including full experimental procedures, analytical data, complete references section and most useful for synthetic organic chemists.