Formal synthesis of semiaquilegin A

A formal synthesis of semiaquilegin A is achieved starting from readily available oridonin in 19 linear steps. The absolute configuration of the natural product has been established. A variety of useful analogues were prepared through this synthetic route.     

A new method for introduction w-side chain of prostanoid using Barton radical reaction

A new method for introduction w-side chain of prostanoid was described in this note. Starting from acid chloride (3), via Barton radical reaction, a trans α,β-unsaturated ketone sython was introduced.     

Working with Sir Derek H. R. Barton. “Chemistry,through Chemistry and For Chemistry”

The author reports on his experience as editor of Derek H. R. Barton's autobiography, Some Recollections of Gap Jumping, and video documentary of Barton produced less than a year before Barton's death on March 16, 1998.     

A novel Barton decarboxylation produces a 1,4-phenyl radical rearrangement domino reaction

A novel 1,4-Phenyl radical rearrangement (1,4-PhRR) is described in a typical Barton decarboxylation procedure. While carrying out this reaction in presence of a N,N-disubstituted β-amino acid derivative, the decarboxyphenyl rearranged derivative is obtained, as well as in presence of β-N,N-acylamide. On the other hand, secondary amines give the β-lactam derivative without rearrangement, as well as N-Fmoc derivatives give the normal decarboxylation reaction. In regards of amines which are far away from the carboxylic group, such as δ-amino acid derivatives, the reaction occur through a typical Barton decarboxylation without rearrangement. The diversity of the reaction proves synthetic usefulness paving the way to interesting biologically active compounds.     

Total synthesis of (+)-lentiginosine from d-glucose

A total synthesis of (+)-lentiginosine, a potent and selective amyloglucosidase inhibitor, is reported from a d-glucose-derived epoxide in 38% overall yield. In this synthesis, ambient conditions and readily available starting materials and reagents are used.     

A new method for introduction ω-side chain of prostanoid using Barton radical reaction

A new method for introductionω-/side chain of prostanoid was described in this note.Starting from acid chloride(3),via Barton radical reaction,a transα,β-unsaturated ketone sython was introduced.     

Free Radical Chemistry. 13 [1] Addition of Alkyl‐Cyclohexanol Derivatives to Hexafluoropropene

Free radicals derived from some alkyl substituted cyclohexanol derivatives react with hexafluoropropene to give a variety of polyfluoroalkylated adducts. Stereochemistry of the processes is discussed and remote functionalisation of the methyl group in 2‐methylcyclohexanol by an unusual intramolecular hydrogen atom transfer process is reported.     

Nucleosides XIII. Facile Synthesis of 4‐Amino‐1‐(2‐deoxy‐β‐D‐ribofuranosyl)quinazolin‐2‐one as a 2′‐Deoxycytidine Analog for Oligonucleotide Synthesis

4‐Amino‐1‐(2‐deoxy‐β‐D‐ribofuranosyl)quinazolin‐2‐one (4) was prepared by Barton deoxygenation from 4‐amino‐1‐(β‐D‐ribofuranosyl)quinazolin‐2‐one (3) as a 2′‐deoxycytidine analog.     

Formal Synthesis of Vallesamidine

A novel route to the racemic selenide (1RS,12bRS)‐1‐ethyl‐2,3,6,7,12,12b‐hexahydro‐1‐[2‐(phenylseleno)ethyl]indolo[2,3‐a]quinolizin‐4(1H)‐one ( 13b ), a key intermediate in the total synthesis of vallesamidine ( 1 ), was elaborated. Compound 3a , obtained by Pictet–Spengler reaction of tryptamine and cyclohept‐4‐enyl‐1‐carbaldehyde ( 2c ), was oxidized with KMnO₄ to the diacid 4 , which was subsequently converted into the isomeric tetracyclic lactams 5a,b . After proper protection maneuvers, Barton decarboxylation of 10a,b , trapping with PhSe₂Ph, and Boc removal afforded 13b .