l-Rhamnose was converted, over a 13-step-sequence, into 2′-O-acetyl-N 2-(N,N-dimethylaminomethylene)-1′-O-(4-methoxybenzyl)-3-[2-(4-nitrophenyl)ethyl]-l-biopterin, an appropriately protected precursor of 1′-O- and 2′-O-monoglycosyl-l-biopterin. Thus, the first selective synthesis of these l-biopterin glycosides was accomplished by treatment of the precursor with either DDQ or sodium methoxide, then with tetra-O-benzoyl-α-d-glucopyranosyl bromide in the presence of silver triflate and tetramethylurea, followed by removal of the remaining protecting groups.
l-
鼠李糖通过13步反应转化为2′-O-乙酰基-N 2-(N,N-二
甲基氨基甲基亚甲基)-1′-O-(4-甲氧基苄基)-3-[2-(4-
硝基苯基)乙基]-l-
生物蝶呤,这是1′-O-和2′-O-
单糖基-l-
生物蝶呤的适当保护前体。因此,这些l-
生物蝶呤糖苷的首次选择性合成是通过用
DDQ或
甲醇钠处理前体,然后在
三氟甲磺酸银和四甲基
脲存在下用四-O-苯甲酰基-Β-d-
吡喃
葡萄糖溴化物处理,最后去除剩余的保护基团。