938082-00-9Relevant articles and documents
Intramolecular 1,8-hydrogen-atom transfer reactions in (1→4)-O- disaccharide systems: Conformational and stereochemical requirements
Francisco, Cosme G.,Herrera, Antonio J.,Kennedy, Alan R.,Martin, Angeles,Melian, Daniel,Perez-Martin, Ines,Quintanal, Luis M.,Suarez, Ernesto
supporting information; experimental part, p. 10369 - 10381 (2009/10/16)
The stereochemical and conformational factors controlling the intramolecular hydrogen-atom transfer (HAT) reaction between the two pyranose units in a (1→4)-O-disaccharide when promoted by a primary 6-O-yl radical are studied. Models with α-D-Glcp-(1→4)-β-D-Glcp, α-L-Rhamp-(1→ 4)-α-D-Galp or α-D-Manp-(1→4)-β- L-Gulp skeletons led exclusively to the abstraction of the hydrogen from H-C-5' and the formation, through a nine-membered transition state, of a 1,3,5-trioxocane ring system in a stable boat-chair conformation. Notwithstanding, derivatives of α-L-Rhamp-(1→4)-α-D-Glcp or α-D-Manp-(1→4)-α-D-Galp exclusively abstract the hydrogen from H-C-1' through a seven-membered transition state and, therefore, lead to an interglycosidic spiro ortho ester.
Intramolecular 1,8- Versus 1,6-hydrogen atom transfer between pyranose units in a (1→4)-disaccharide model promoted by alkoxyl radicals. Conformational and stereochemical requirements
Martin, Angeles,Perez-Martin, Ines,Quintanal, Luis M.,Suarez, Ernesto
, p. 1785 - 1788 (2008/02/02)
The stereochemical and conformational factors controlling the intramolecular hydrogen atom transfer (HAT) reaction between the two pyranose units in a (1→4)-disaccharide when promoted by a primary 6-0-yl radical are studied. Models with α-D-Glcp-(1→4)-β-D
