Baker's yeast-mediated approach to (−)-cis- and (+)-trans-Aerangis lactones
摘要:
The first enantioselective synthesis of natural (-)-cis-Aerangis lactone (-)-1a and its (+)-trans-diastereoisomer (+)-lb is described. The key steps in the synthesis are: (i) the enantiospecific and 100% diastereoselective baker's yeast reduction of 1,4-keto acid 2, to afford enantiopure trans- cognac lactone (+)-10; (ii) the regioselective PPL-mediated hydrolysis of the primary acetate moiety of diacetate (+)-(3S,4R)-3, obtained from (+)-10. Chain elongation by one carbon atom via cyanide substitution, and inversion of the configuration of C(5) in nitrile derivative (+)-21a are also required to complete the synthetic route to (-)-1a. (C) 2001 Elsevier Science Ltd. All rights reserved.
The dimesitylboron group in organic synthesis 8. Preparations of 1,3-diols from oxiranes
作者:Andrew Pelter、Gina Bugden、Richard Rosser
DOI:10.1016/s0040-4039(01)80862-5
日期:1985.1
Alkyldimesitylboranes, yield anions1, Mes2BCHR, that on reaction with oxiranes followed by oxidation give 1,3-diols. These anions are thus the operational equivalent of RCHOH. The scope and limitations of the new process are delineated.
2-Iodoxybenzoic Acid Mediated Facile Conversion of 1,3-Diols to 1,2-Diketones by Oxidative Cleavage of the C-C Bond
作者:J. Yadav、Swapan Biswas、R. Srinivas
DOI:10.1055/s-2006-950372
日期:——
1,3-Diols undergo smooth oxidative cleavage of the C-C bond in the presence of 2-iodoxybenzoic acid (IBX) affording 1,2-diketones in excellent yields under mild conditions.
1,3-二醇在 2-碘氧基苯甲酸 (IBX) 存在下顺利氧化裂解 CC 键,在温和条件下以优异的产率生成 1,2-二酮。
BIO-BASED POLYESTER LATEX
申请人:OCE-Technologies B.V.
公开号:EP2686366B1
公开(公告)日:2019-12-25
JPH07157530A
申请人:——
公开号:JPH07157530A
公开(公告)日:1995-06-20
OLFACTORY TEST SYSTEMS AND METHODS
申请人:Olfaxis, LLC
公开号:US20200253531A1
公开(公告)日:2020-08-13
Methods, devices and systems for evaluating olfactory function are configured to: electronically estimate a user-specific odorant detection threshold sensitivity threshold using at least one target stimulus odorant delivered to a nose of a user; flowably deliver a plurality of different target stimulus odorants to the nose of the user with defined concentrations of the different target stimulus odorants based, at least in part, on the estimated user-specific odorant detection sensitivity threshold; and evaluate olfactory function of the user based on the user's response to the delivered different target stimulus odorants.