1.Urea, polymer with ammonium chloride , cyanoguanidine and formaldehyde;
名称 脲与氯化铵;胍和甲醛的聚合物;
2.Cyanoguanidine and acetylated β-D-ribose were used as starting materials to give target compound via salt formation, cyclization, silylation, coupling reaction and deprotection.