185517-21-9Relevant articles and documents
A concise and efficient route to the Alzheimer's therapeutic agent (R)-arundic acid
García, Jesús M.,Odriozola, José M.,Lecumberri, Ainara,Razkin, Jesús,González, Alberto
, p. 10664 - 10669 (2008)
A short and efficient procedure for the preparation of (R)-arundic acid, a therapeutic agent for the treatment of Alzheimer's disease, has been developed. Based on cheap and commercially available (1R)-(+)-camphor as the source of chiral information, (R)-arundic acid is synthesized in a four-step cyclic sequence with 55% overall yield and high optical purity, ≥98% ee. Alkyl halide and acetylene constitute the only consumable carbon sources of this method, which allows obtaining of both enantiomers and recycling of chiral auxiliary.
A new process for synthesis of the astrocyte activation suppressor, ONO-2506
Hasegawa, Tomoyuki,Kawanaka, Yasufumi,Kasamatsu, Eichi,Ohta, Chisa,Nakabayashi, Kazuhiro,Okamoto, Masaki,Hamano, Masaya,Takahashi, Keiji,Ohuchida, Shuichi,Hamada, Yasumasa
, p. 774 - 781 (2005)
Development of a new process for the synthesis of ONO-2506, an agent that suppresses astrocyte activation, is described. Previous processes that involved asymmetric synthesis with a chiral auxiliary were unsatisfactory from a cost perspective because the relatively expensive chiral auxiliaries were not recyclable. To develop a more cost-effective process, we designed a new process starting from chiral 1,2-epoxyoctane, which was readily prepared catalytically by Prof. Jacobsen's method. The new five-step process was developed with the establishment of a modified cyanation condition, in which lithium cyanide was prepared in situ by combining lithium hydroxide with acetone cyanohydrin. Then the mechanisms for racemization and the side reaction until the cyanation step were clarified, and these problems were solved. The main features of this process are crystallization of the amide intermediate, since its optical purity is readily improved by recrystallization up to 100% ee in addition to formation of the dibenzylamine salt with ONO-2506 that leads to improved chemical and optical purity of the final product The shorter synthesis, including a one-pot reaction was ruled out because of the hazardous nature of the Katriztky hydrolysis conditions for the conversion of nitrile to amide in the presence of sodium cyanide.
Stereodivergent approach to Alzheimer's therapeutic agent (R)-(?) and (S)-(+)-arundic acid employing chiral 4-pentenol derivatives as building blocks
Bhosale, Viraj A.,Waghmode, Suresh B.
, p. 2342 - 2348 (2017)
An efficient stereodivergent total synthesis of anti-Alzheimer agent (R)-(?) and (S)-(+)-arundic acid has been achieved from both chiral and nonchiral materials. This strategy features an efficient approach to separable diastereomeric C-2 chiral 4-pentenol intermediates employing proline catalysed asymmetric α-aminooxylation and [3,3] sigmatropic Claisen rearrangement are the highlights of present synthesis.
PROCESSES FOR THE SYNTHESIS OF CHIRAL 1-ALKANOLS
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Paragraph 0242; 0243, (2016/12/01)
The invention relates to highly enantioselective processes for the synthesis of chiral 1-alkanols via Zr-catalyzed asymmetric carboalumination of alkenes.
Widely applicable synthesis of enantiomerically pure tertiary alkyl-containing 1-alkanols by zirconium-catalyzed asymmetric carboalumination of alkenes and palladium- or copper-catalyzed cross-coupling
Xu, Shiqing,Lee, Ching-Tien,Wang, Guangwei,Negishi, Ei-Ichi
, p. 1829 - 1835 (2013/09/02)
A highly enantioselective and widely applicable method for the synthesis of various chiral 2-alkyl-1-alkanols, especially those of feeble chirality, has been developed. It consists of zirconium-catalyzed asymmetric carboalumination of alkenes (ZACA), lipase-catalyzed acetylation, and palladium- or copper-catalyzed cross-coupling. By virtue of the high selectivity factor (E) associated with iodine, either (S)- or (R)-enantiomer of 3-iodo-2-alkyl-1- alkanols (1), prepared by ZACA reaction of allyl alcohol, can be readily purified to the level of ≥99 % ee by lipase-catalyzed acetylation. A variety of chiral tertiary alkyl-containing alcohols, including those that have been otherwise difficult to prepare, can now be synthesized in high enantiomeric purity by Pd- or Cu-catalyzed cross-coupling of (S)-1 or (R)-2 for introduction of various primary, secondary, and tertiary carbon groups with retention of all carbon skeletal features. These chiral tertiary alkyl-containing alcohols can be further converted into the corresponding acids with full retention of the stereochemistry. The synthetic utility of this method has been demonstrated in the highly enantioselective (≥99 % ee) and efficient syntheses of (R)-2-methyl-1-butanol and (R)- and (S)-arundic acids. Look, mom, one hand! 2-Alkyl-1-alkanols of feeble chirality have been synthesized by a sequence of zirconium-catalyzed asymmetric carboalumination of alkenes (ZACA), lipase-catalyzed acetylation, and Pd- or Cu-catalyzed cross-coupling in high enantiomeric purity of ≥99 % ee. The synthetic utility of this method has been demonstrated in highly enantioselective and efficient syntheses of (R)-2-methyl-1-butanol, (R)- and (S)-arundic acids. Copyright
