64520-57-6Relevant academic research and scientific papers
Stereoselective synthesis of a new trihydroxyindolizidine lactone
Pisaneschi, Federica,Piacenti, Michela,Cordero, Franca M.,Brandi, Alberto
, p. 292 - 296 (2006)
A general approach to 1,6,7-trihydroxyindolizidin-8-carboxylates is illustrated through the synthesis of a γ-lactone in an enantiopure form in seven steps starting from (3S)-3-t-butyloxy-1-pyrroline N-oxide and the acetonide of (2E,4S)-4,5-dihydroxy-2-pentenoic acid derived from (S)-malic acid and mannitol, respectively. The process was completely stereoselective and allowed the total control of the relative and absolute configuration of the five contiguous stereocentres of the product.
Palladium-catalyzed tandem heck-lactonization from o-iodophenols and enoates: Synthesis of coumarins and the study of the mechanism by electrospray ionization mass spectrometry
Fernandes, Talita De A.,Gontijo Vaz, Boniek,Eberlin, Marcos N.,Da Silva, Alcides J. M.,Costa, Paulo R. R.
scheme or table, p. 7085 - 7091 (2010/12/25)
The tandem Heck-lactonization reaction between enoates Z-1a,b, E-1a, E-2a-d, Z-2e, 2f, and o-iodophenols (4a-f) was studied in the presence of substoichiometric amounts of Pd(OAc)2 or PdCl2, under experimental conditions favoring the cationic mechanism (conditions A, B, and C), leading to coumarins 5a-f and 6a-e. Moderate to excellent yields were obtained under aqueous conditions (conditions A and B). Using electrospray ionization for transferring ions directly from solution to the gas phase, and mass spectrometry for structural assignments, key cationic palladium intermediates have been successfully intercepted and structurally characterized for the first time for this type of reaction.
