1057663-19-0Relevant articles and documents
A Concise Enantiodivergent Synthesis of Equol
Uemura, Takahito,Saito, Yusuke,Sonoda, Motohiro,Tanimori, Shinji
, p. 693 - 696 (2021)
Equol, a nonsteroidal estrogen produced from the metabolism of the isoflavonoid phytoestrogen daidzein, has been synthesized as both enantioenriched forms based on MacMillan's α-Arylation of carbonyl compound mediated by amino acid derived indazolidinones and copper precatalysts. The natural form of (S)-equol and its enantiomer (R)-equol have been synthesized in 8 steps from 2,4-dimethoxybenzaldehyde with good enantiomeric purity (90% ee and 90% ee, respectively).
Enantioselective iridium-catalyzed hydrogenation of α-arylcinnamic acids and synthesis of (S)-equol
Yang, Shuang,Zhu, Shou-Fei,Zhang, Can-Ming,Song, Song,Yu, Yan-Bo,Li, Shen,Zhou, Qi-Lin
, p. 5172 - 5178 (2012/07/31)
By using iridium catalyst based on chiral spiro phosphine-oxazoline ligands, the hydrogenation of α-arylcinnamic acids was accomplished under ambient pressure and low catalyst loading (as low as 0.01 mol %), providing useful 2,3-diarylpropionic acids in high yields with excellent enantioselectivities (up to 99% ee). A catalytic enantioselective synthesis of (S)-equol with the present hydrogenation reaction as a key step was accomplished starting from commercially available starting materials in six steps with 48.4% overall yield.
Synthetic access to optically active isoflavans by using allylic substitution
Takashima, Yuji,Kaneko, Yuki,Kobayashi, Yuichi
experimental part, p. 197 - 207 (2010/03/03)
A general approach to the (S)- and (R)-isoflavans was invented, and efficiency of the method was demonstrated by the synthesis of (S)-equol ((S)-3), (R)-sativan ((R)-4), and (R)-vestitol ((R)-5). The key step is the allylic substitution of (S)-6a (Ar1=2,4-(MeO)2C6H3) and (R)-6b (Ar1=2,4-(BnO)2C6H3) with copper reagents derived from CuBr·Me2S and Ar2-MgBr (7a, Ar2=4-MeOC6H4; 7b, 2,4-(MeO)2C6H3; 7c, 2-MOMO-4-MeOC6H3), furnishing anti SN2′ products (R)-8a and (S)-8b,c with 93-97% chirality transfer in 60-75% yields. The olefinic part of the products was oxidatively cleaved and the Me and Bn groups on the Ar1 moieties was then removed. Finally, phenol bromide 9a and phenol alcohols 9b,c underwent cyclization with K2CO3 and the Mitsunobu reagent to afford (S)-3 and (R)-4 and -5, respectively.
New synthetic route to (S)-(-)-equol through allylic substitution
Takashima, Yuji,Kobayashi, Yuichi
, p. 5156 - 5158 (2008/12/20)
Allylic substitution of allylic picolinate 5 with a copper reagent derived from p-MeOC6H4MgBr (6) and CuBr·Me2S produced the anti SN2′ product 7 with high regioselectivity and efficient chirality transfer. Oxidative cleavage of the olefinic function to the alcohol followed by bromination afforded bromide 16, which upon demethylation and intramolecular ether ring formation furnished (S)-(-)-equol (3).
