Nucleophilic substitution at the anomeric position of 1,2-O-isopropylidenefuranose derivatives. A novel stereoselective synthesis of cyclic phosphates analogous to cAMP.
1,2-O-Isopropylidenefuranose derivatives were treated with various nucleophiles in the presence of either BF(3).OEt(2) or trimethylsilyl trifluoromethanesulfonate (TMSOTf) leading to substitution products in a regio- and stereoselective manner. In particular, nucleophilic substitution of 1,2-O-isopropylidenefuranose derivatives when treated with allyltrimethylsilane was controlled by steric and electronic factors (similar to Woerpel's stereoelectronic model). On the other hand, when 1,2-O-isopropylidenefuranose derivatives were treated with trimethylsilane, in the presence of bis-O-trimethylsilyl-5-iodouracil or bis-O-trimethylsilyl-thymidine, substitution products were generated in high regio- and stereoselectivities via an unusual nucleophilic substitution with opening of the furanose ring. Based on these results, a stereoselective method for the synthesis of neutral cyclic phosphates analogous to cAMP was developed.
Romero
Miriam
M
Centro de Investigación de la Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, 14 Sur Esq. San Claudio, Col. San Manuel, 72570 Puebla, Mexico.
Hernández
Luís
L
Quintero
Leticia
L
Sartillo-Piscil
Fernando
F
D001880:Boranes / Q000737:chemistry; D000242:Cyclic AMP / Q000031:analogs & derivatives*; D004986:Ether / Q000737:chemistry; D008698:Mesylates / Q000737:chemistry; D009712:Nucleotides, Cyclic / Q000138:chemical synthesis*; D012266:Ribose / Q000031:analogs & derivatives* / Q000737:chemistry; D013237:Stereoisomerism; D014297:Trimethylsilyl Compounds / Q000737:chemistry
D001880:Boranes; D008698:Mesylates; D009712:Nucleotides, Cyclic; D014297:Trimethylsilyl Compounds; D004986:Ether; C053353:trimethylsilyl trifluoromethanesulfonate; D012266:Ribose; C021274:boron trifluoride; C440774:allyltrimethylsilane; D000242:Cyclic AMP