Lithiation at the 6-position of uridine with lithium hexamethyldisilazide: crucial role of temporary silylation.
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]
Yoshimura
Yuichi
Y
Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-Ku, Sendai 981-8558, Japan. yoshimura@tohoku-pharm.ac.jp
Kumamoto
Hiroki
H
Baba
Ayuka
A
Takeda
Shingo
S
Tanaka
Hiromichi
H
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*
D002712:Chlorides; D018020:Lithium Compounds; D012821:Silanes; D008094:Lithium; C442341:lithium hexamethyldisilazide; D014529:Uridine