title: The 4-methylthio-1-butyl group for phosphate/thiophosphate protection in oligodeoxyribonucleotide synthesis.
abstract: The detailed preparation of deoxyribonucleoside phosphoramidites functionalized with a 4-methylthio-1-butyl group for P(III) protection is described, along with the incorporation of these phosphoramidites into DNA oligonucleotides via solid-phase techniques. The versatility of the thermolabile 4-methylthio-1-butyl phosphate/thiophosphate-protecting group is exemplified through its facile removal from oligonucleotides under neutral conditions or under standard basic conditions. The sulfonium salt that is produced during the thermolytic deprotection of oligonucleotides did not alter DNA nucleobases or desulfurize phosphorothioate diesters to a significant extent.
authors.affiliation: Food and Drug Administration, Bethesda, Maryland, USA.
authors.forename: Jacek
authors.initials: J
authors.lastname: Cieślak
authors.forename: Andrzej
authors.initials: A
authors.lastname: Grajkowski
authors.forename: Victor
authors.initials: V
authors.lastname: Livengood
authors.forename: Serge L
authors.initials: SL
authors.lastname: Beaucage
mesh_terms: D006358:Hot Temperature; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis* / Q000737:chemistry; D009943:Organophosphorus Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*
chemical_list: D009838:Oligodeoxyribonucleotides; D009943:Organophosphorus Compounds; D010710:Phosphates; C434331:phosphoramidite; C035638:thiophosphoric acid