Tetramethylsuccinimide as a Directing/Protecting Group in Purine Glycosylations
摘要:
Tetra methylsuccinic anhydride can be used to protect the exocyclic amine of 6-aminopurine derivatives by forming the corresponding tetramethysuccinimide. X-ray crystallography confirms that the imide carbonyl and the methyl groups are positioned to sterically block the N7 nitrogen so that glycosylations occur with very high regiochemical control at N9. This approach Is particularly effective for 3-substituted purines where the substituent tends to block access to N9 and inhibit glycosylation at that site.
Tetramethylsuccinimide as a Directing/Protecting Group in Purine Glycosylations
摘要:
Tetra methylsuccinic anhydride can be used to protect the exocyclic amine of 6-aminopurine derivatives by forming the corresponding tetramethysuccinimide. X-ray crystallography confirms that the imide carbonyl and the methyl groups are positioned to sterically block the N7 nitrogen so that glycosylations occur with very high regiochemical control at N9. This approach Is particularly effective for 3-substituted purines where the substituent tends to block access to N9 and inhibit glycosylation at that site.
2,3-Dicyclohexylsuccinimide as a directing/protecting group for the regioselective glycosylation or alkylation of purines
作者:Ayan Pal、Kerry J. Salandria、Joseph W. Arico、Mark K. Schlegel、Larry W. McLaughlin
DOI:10.1039/c3cc37265k
日期:——
Here we describe the synthesis and application of a novel 2,3-dicyclohexylsuccinimide (Cy2SI) protecting group towards regioselective purine glycosylation and alkylation reactions. This bulky protecting group promotes high regioselectivity during the glycosylation (as well as diastereoselectivity) or alkylation of purines using Hoffer's chlorosugar or tert-butyl bromoacetate, respectively. Cy2SI offers the additional synthetic advantage that other base-labile protecting groups, such as toluoyl esters, can be selectively removed in its presence without affecting the imide.
Tetramethylsuccinimide as a Directing/Protecting Group in Purine Glycosylations
作者:Joseph W. Arico、Amy K. Calhoun、Kerry J. Salandria、Larry W. McLaughlin
DOI:10.1021/ol9025028
日期:2010.1.1
Tetra methylsuccinic anhydride can be used to protect the exocyclic amine of 6-aminopurine derivatives by forming the corresponding tetramethysuccinimide. X-ray crystallography confirms that the imide carbonyl and the methyl groups are positioned to sterically block the N7 nitrogen so that glycosylations occur with very high regiochemical control at N9. This approach Is particularly effective for 3-substituted purines where the substituent tends to block access to N9 and inhibit glycosylation at that site.