Towards synthesis of biologically important phosphate analogues : exploring H-phosphonate and C-phosphonate chemistry

Sammanfattning: This thesis is based on studies directed towards the development of methods for the preparation of phosphorus containing natural products, with the focus on C-phosphonate nucleic acid analogues.Mechanistic studies concerning formation of the phosphorus-carbon bond resulted in development of two efficient protocols for the synthesis of C-phosphonates from the corresponding H-phosphonate derivatives. These were applied, inter alia, to the synthesis of a novel type of nucleotide analogue containing the 4-pyridylphosphonate internucleotide bond. Also, synthesis of new nucleoside 5'-methylenephosphonate building blocks, suitable for incorporation into oligonucleotides or their conjugates, and a new method for the preparation of alkyl H-phosphonates, are discussed. Finally, mechanistic investigations related to C-phosphonates formation via N->C phosphorus migration in certain complexes of DBU with chlorophosphates, are presented.