Regioselective Synthesis of Phosphonylated Sugars from Reactions of Glycals with Diphenylphosphenium Cation
摘要:
Reaction of methyl 4,6-di-O-acetyl-2,3-dideoxy-D-erythro-hex-2-enopyranoside 1 with two equivalents of diphertylphosphenium cation at 0degreesC gave the 1-phosphonylated 2-enopyranos ides 3alpha and 3beta as major products. Similarly, reaction of diphenylphosphenium cation with tri-O-acetylglycal afforded the same products in a similar ratio. In contrast, a reaction with tri-O-benzylglucal at reflux temperature of dichloromethane afforded the 3-phosphonylated sugar 13 as a major product. These reactions may proceed via stable allyl cations.
Fragmentation of Carbohydrate Anomeric Alkoxyl Radicals: Synthesis of Chiral Polyhydroxylated β-Iodo- and Alkenylorganophosphorus(V) Compounds
作者:Daniel Hernández-Guerra、María S. Rodríguez、Ernesto Suárez
DOI:10.1002/ejoc.201402387
日期:2014.8
A direct approach to β-iodophosphonates and β-iodophosphine oxides from 2,3-dideoxy-3-phosphoryl carbohydrate derivatives has been achieved by using the anomeric alkoxyl radical 1,2-fragmentation protocol. The reaction has been conducted on carbohydrate derivatives under mild conditions with (diacetoxyiodo)benzene and molecular iodine. Subsequent dehydroiodination afforded the corresponding vinylphosphonates
Synthesis of Chiral β-Iodo- and Vinylorganophosphorus(V) Compounds by Fragmentation of Carbohydrate Anomeric Alkoxyl Radicals
作者:Daniel Hernández-Guerra、María S. Rodríguez、Ernesto Suárez
DOI:10.1021/ol302939z
日期:2013.1.18
synthesis of chiral vinylphosphonate and vinylphosphine oxide carbohydrate derivatives has been developed using the anomeric alkoxyl radical fragmentation reaction as the key step. The synthetic sequence proceeded via β-iodophosphonate and β-iodophosphine oxide intermediates, which may be interesting synthons for the introduction of phosphorus into organic molecules. These vinylphosphonates could be easily
Reaction of methyl 4,6-di-O-acetyl-2,3-dideoxy-D-erythro-hex-2-enopyranoside 1 with two equivalents of diphertylphosphenium cation at 0degreesC gave the 1-phosphonylated 2-enopyranos ides 3alpha and 3beta as major products. Similarly, reaction of diphenylphosphenium cation with tri-O-acetylglycal afforded the same products in a similar ratio. In contrast, a reaction with tri-O-benzylglucal at reflux temperature of dichloromethane afforded the 3-phosphonylated sugar 13 as a major product. These reactions may proceed via stable allyl cations.