410087-00-2Relevant academic research and scientific papers
Enantioselective aldehyde α-nitroalkylation via oxidative organocatalysis
Wilson, Jonathan E.,Casarez, Anthony D.,MacMillan, David W. C.
, p. 11332 - 11334 (2011/03/21)
(Chemical Equation Presented) The first enantioselective organocatalytic α-nitroalkylation of aldehydes has been accomplished. The aforementioned process involves the oxidative coupling of an enamine intermediate, generated transiently via condensation of an amine catalyst with an aldehyde, with a silyl nitronate to produce a β-nitroaldehyde. Two methods, one that furnishes the syn β-nitroaldehyde and a second that provides access to the anti isomer, have been developed. Data are presented to support a hypothesis that explains this phenomenon in terms of a silyl group-controlled change in mechanism. Finally, a three-step procedure for the synthesis of both syn- and anti-α,β-disubstituted β-amino acids is presented.
Kulokekahilide-1, a cytotoxic depsipeptide from the cephalaspidean mollusk Philinopsis speciosa
Kimura, Junji,Takada, Yuuki,Inayoshi, Tomoko,Nakao, Yoichi,Goetz, Gilles,Yoshida, Wesley Y.,Scheuer, Paul J.
, p. 1760 - 1767 (2007/10/03)
The cytotoxic depsipeptide kulokekahilide-1, which contains two unusual amino acids, 4-phenylvaline and 3-amino-2-methylhexanoic acid, was isolated from the cephalaspidean mollusk Philinopsis speciosa. Structure elucidation of kulokekahilide-1 was carried out by spectroscopic analysis and chemical degradation. The absolute stereochemistry was determined by Marfey analysis for amino acids and chiral HPLC analysis for hydroxy acids. All four stereoisomers of 4-phenylvaline and 3-amino-2-methylhexanoic acid, which were necessary for Marfey analysis, were synthesized by use of the Heck reaction and Evans's method, respectively. Kulokekahilide-1 showed cytotoxicity against P388 murine leukemia cells with an IC50 value of 2.1 μg/mL.
