enosine (5) gives fully protected P-chiral 2'-deoxyadenylyl(3',5') 2'-deoxyadenosine S-methylphosphorothioates (6), ¦(Sp)-6:(Rp)-6=92:8 and (Sp)-6:(Rp)-6-32:68 respectively ¦.Demethylation of internucleotide S-methylphosphorothioate group in 6 and deprotection of 3'- and 5'-hydroxyl functions lead to diastereoisomeric mixture of 2'-deoxyadenylyl (3',5') 2'-deoxyadenosine-O, O-phosphorothioates (7)
5'-O-单甲氧基三苯甲基-
2'-脱氧腺苷3'-O-βO-(4-
硝基苯基)-S-甲基-
硫代磷酸酯(4)β(Sp)-4的
磷原子上的4-
硝基苯氧基取代:通过3'-O-叔丁基二甲基甲
硅烷基-
2'-脱氧腺苷的碱活化5'-羟基官能团,(Rp)-4 = 90:10和(Sp)-4:(Rp)-4 = 30:70κ (5)得到完全保护的P-手性
2'-脱氧腺苷基(3',5')
2'-脱氧腺苷S-甲基
硫代磷酸酯(6),Φ(Sp)-6:(Rp)-6 = 92:8和(Sp )-6:(Rp)-6-32:68γ.6中的核苷酸间S-甲基
硫代磷酸酯基的去甲基化和3'-和5'-羟基官能团的脱保护作用导致
2'-脱氧腺苷基(3', 5′)2′-脱氧
腺苷-O,O-
硫代磷酸酯(7)。