Synthesis of 2?-Deoxyribofuranosides of 8-Aza-7-deazaguanine and Related Pyrazolo[3,4-d]pyrimidines
作者:Frank Seela、Herbert Steker
DOI:10.1002/hlca.19860690714
日期:1986.10.29
N(1)-and N(2)-substituted 4-thioxo analogues 17a and 18a, respectively. The ratio of N(1)- to N(2)-glycosylation was 2:1 for 7c and 1:1 for 7a, viz. depending on the nucleobase structure. The rate of the H+-catalyzed N-glycosyl hydrolysis was strongly decreased for the N(2)-(β-D-2′-deoxyribofuranosides) as compared to the N(1)-compounds. However, the N(1)-nucleoside 1, which is an isostere of 2′-deoxyguanosine
所述Ñ(1) -和Ñ(2) - (2'- deoxyribofuranosides)1和2,分别为8-氮杂-7-脱氮鸟嘌呤的制备通过相转移的糖基化在存在或不存在卜4 NHSO 4作为6-氨基-4-甲氧基-1 H-吡唑并[3,4- d ]嘧啶(7c)与2-脱氧-3,5-二-O-(对甲苯甲酰基)-α-D-赤型-的催化剂戊呋喃糖酰氯(10)。以类似的方式,但是没有催化剂并且使用THF作为有机相,6-氨基-4-氯核苷11b和12b从7a合成并分别转化为N(1)-和N(2)-取代的4-thioxo类似物17a和18a。的比率Ñ(1) -至Ñ(2)-glycosylation为2:1 7C和1:1为图7a,即 取决于核碱基的结构。与N(1)化合物相比,N(2)-(β-D-2'-脱氧核糖呋喃糖苷)的H +催化N-糖基水解速率大大降低。但是,N(1)-核苷1它是2'-脱氧鸟苷的等排物,具有足够的稳定性,可稍后用于固相寡核苷酸合成。