title: Lithiation at the 6-position of uridine with lithium hexamethyldisilazide: crucial role of temporary silylation.
abstract: Lithium hexamethyldisilazide (LiHMDS) can mediate silylation at the 6-position of uridine, although LiHMDS alone is not able to generate the C-6-lithiated uridine. Experimental results showed that temporary silylation of O-4 (or N-3) of the uracil ring triggers the C-6 lithiation with LiHMDS. This finding allowed us to develop an efficient intramolecular alkylation of 5'-deoxy-5'-iodouridine to furnish 6,5'-C-cyclouridine. [reaction--see text]
authors.affiliation: Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-Ku, Sendai 981-8558, Japan. yoshimura@tohoku-pharm.ac.jp
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Yoshimura
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kumamoto
authors.forename: Ayuka
authors.initials: A
authors.lastname: Baba
authors.forename: Shingo
authors.initials: S
authors.lastname: Takeda
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D002712:Chlorides / Q000737:chemistry; D003500:Cyclization; D008094:Lithium / Q000737:chemistry*; D018020:Lithium Compounds / Q000737:chemistry*; D015394:Molecular Structure; D012821:Silanes / Q000737:chemistry*; D014529:Uridine / Q000737:chemistry*
chemical_list: D002712:Chlorides; D018020:Lithium Compounds; D012821:Silanes; D008094:Lithium; C442341:lithium hexamethyldisilazide; D014529:Uridine