192460-94-9Relevant academic research and scientific papers
Catalytic enantioselective total synthesis of (-)-platyphyllide and its structural revision
Hiraoka, Shiharu,Harada, Shinji,Nishida, Atsushi
supporting information; experimental part, p. 3871 - 3874 (2010/07/05)
Figure presented The catalytic asymmetric total synthesis of platyphyllide has been accomplished. A key highly substituted cyclohexene derivative has been obtained by the catalytic asymmetric Diels-Alder reaction of Danishefsky diene with an electron-deficient alkene. The Diels-Alder adduct was converted to a protected cyclohexane-1,3-dione in chiral form by catalytic Ito-Saegusa oxidation. Although the reported structure of platyphyllide was successfully synthesized, the optical rotation was opposite that of the natural compound. The absolute configuration of natural (-)-platyphyllide is revised to be a (6S,7S)-enantiomer.
An investigation of the behaviour of α,β-unsaturated sulfoxides in the presence of trimethylsilyl iodide
Aversa, Maria C.,Barattucci, Anna,Bonaccorsi, Paola,Giannetto, Placido
, p. 10145 - 10150 (2007/10/03)
A mild, efficient and seemingly general method for converting α,β-unsaturated sulfoxides into carbonyl compounds by means of trimethylsilyl iodide (TMSI) is described. Experiments on different substrates and trimethylsilyl halides lead to the conclusion that the oxidation state of the sulfur atom, on one hand, and halogen kind in TMSX on the other, assume a determining role in the progression of the reaction. The ease of experimental procedure, the possibility of 1H NMR monitoring, and good yields of final products constitute advantages of the TMSI-promoted conversion of α,β-unsaturated sulfoxides into carbonyl compounds.
Unexpected conversion of vinyl sulfoxides into carbonyl compounds by means of iodotrimethylsilane
Aversa, Maria C.,Barattucci, Anna,Bonaccorsi, Paola,Bruno, Giuseppe,Giannetto, Placido,Policicchio, Manuela
, p. 4441 - 4445 (2007/10/03)
The unexpected and previously unknown TMSI-promoted conversion of α,β- unsaturated sulfoxides into carbonyl compounds and disulfides is described. It occurs in good yields under mild conditions. The examples provided support the generality and efficiency of this procedure which acts as a good method for removing the sulfinyl group with the advantage of transforming the vinyl sulfoxides into carbonyl compounds. (C) 2000 Elsevier Science Ltd.
Chiral amino siloxy dienes in the Diels - Alder reaction: Applications to the asymmetric synthesis of 4-substituted and 4,5-disubstituted cyclohexenones and the total synthesis of (-)-α-elemene
Kozmin, Sergey A.,Rawal, Viresh H.
, p. 9562 - 9573 (2007/10/03)
Described is a study of the preparation, reactivity, and diastereoselectivity of chiral 1-amino-3-siloxy-1,3-butadienes in the Diels - Alder reaction. These dienes were easily prepared in good yield from the corresponding enantiomerically pure substituted pyrrolidines. All the dienes described underwent cycloadditions readily with several activated dienophiles under mild reaction conditions. An amino siloxy diene containing a C2-symmetric 2,5-diphenylpyrrolidine auxiliary was found to provide high diastereofacial control, even at or above room temperature. Upon hydrolysis of the cycloadducts, 4-substituted and 4,5-disubstituted cyclohexenones were obtained with ee's ranging from 85% to >98%. A simple model based primarily on steric arguments was developed to rationalize and predict the absolute configurations of final products obtained by this sequence. The synthetic utility of the methodology was illustrated through a concise enantioselective synthesis of (-)-α-elemene. The synthesis also served to establish the absolute stereochemistry of the Diels-Alder product of the chiral amino siloxy diene and methacrolein.
