3(5)-(β-d-Ribofuranosyl)pyrazole 1 and 3(5)-(2-deoxy-β-d-ribofuranosyl)pyrazole (2) were stereoselectively synthesized by cyclization of 1,2-diazafulvene intermediates obtained from 2,3,5-tri-O-benzyl-d-ribose (5) and 3,5-di-O-benzyl-2-deoxy-d-ribose (10), respectively.
3(5)-(δ-d-Ribofuranosyl)pyrazole 1 和 3(5)-(2-deoxy-δ-d-ribofuranosyl)pyrazole (2) 是分别通过环化 2,3,5- 三-O-苄基-d-
核糖 (5) 和 3,5- 二-O-苄基-2-脱氧-d-
核糖 (10) 得到的 1,2- 二氮杂烯烃中间体立体选择性合成的。