Stereoselective synthesis of 4'-carbon-substituted xylofuranosyladenines.
Epoxidation of 2',5'-bis-O-silyl-protected N6-pivaloyl-3',4'-unsaturated adenine nucleosides (1, 2 and 3) with dimethyldioxirane uniformly proceeded face-selectively to give the respective 3',4'-beta-epoxides (4, 5 and 6). Ring cleavage of these epoxides examined with Me3Al in CH2Cl2 showed that the TBDMS (4) or TES (5) protected epoxide gave the desired 4'-alpha-methylated product (8 or 10) as the major stereoisomer, while use of the TBDPS protected epoxide (6) resulted in reverse stereoselectivity. Reactions of 4 with other organoaluminum reagents were also carried out.
Kubota
Yutaka
Y
School of Pharmaceutical Sciences, Showa University, 1-5-8 Hadanodai, Shinagawa-ku, Tokyo 142-8555, Japan.
Haraguchi
Kazuhiro
K
Kunikata
Mayumi
M
Hayashi
Mari
M
Ohkawa
Masaomi
M
Tanaka
Hiromichi
H
D000241:Adenosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry; D012833:Siloxanes / Q000737:chemistry; D013237:Stereoisomerism; D013343:Styrenes / Q000737:chemistry
C506477:4-(tert-butyldimethylsiloxy)styrene; D012821:Silanes; D012833:Siloxanes; D013343:Styrenes; C512918:triethylsilane; D002244:Carbon; D000241:Adenosine