An efficient synthesis of the C1−C17 western unit of narasin was achieved from (S)-Roche ester. Highlights in our synthesis include the successful exploitation of three stereoselective sequences of Lewis acid mediated reaction followed by free-radical-based hydrogen transfer.
Design, synthesis and SAR studies of GABA uptake inhibitors derived from 2-substituted pyrrolidine-2-yl-acetic acids
作者:Tobias Steffan、Thejavathi Renukappa-Gutke、Georg Höfner、Klaus T. Wanner
DOI:10.1016/j.bmc.2015.01.035
日期:2015.3
design and synthesis of a series of 2-substituted pyrrolidine-2-yl-acetic acid as core structures and the N-arylalkyl derivatives thereof as potential GABA transport inhibitors. The 2-position in the side chain of pyrrolidine-2-yl-acetic acid derivatives was substituted with alkyl, hydroxy and amino groups to modulate the activity and selectivity to mGAT1 and mGAT4 proteins. SARstudies of the compounds
Highly Stereoselective Aldol Reaction of Chiral 3-(<i>p</i>-Tolylsulfinyl)furfural with Silyl Ketene Acetal Catalyzed by Lanthanide Triflate
作者:Yoshitsugu Arai、Tsutomu Masuda、Yukio Masaki
DOI:10.1055/s-1997-1068
日期:——
The aldol reaction of optically active 3-(p-tolylsulfinyl)furfural with silyl ketene acetal catalyzed by a lanthanide triflate proceeded smoothly to give the syn- and anti-aldol products with high diastereoselectivities in high yield.
Asymmetric Cycloadditions of <i>o</i>-Quinone Methides Employing Chiral Ammonium Fluoride Precatalysts
作者:Ethan Alden-Danforth、Michael T. Scerba、Thomas Lectka
DOI:10.1021/ol802029e
日期:2008.11.6
The catalytic, enantioselective, [4 + 2] cycloaddition reaction of ortho-quinone methides with silyl ketene acetals is described. This mechanistically interesting reaction, initiated by a chiral cinchona alkaloid-derived ammonium fluoride "precatalyst" complex, affords a variety of alkyl- and aryl-substituted 3,4-dihydrocoumarin products in excellent yield and with good enantioselectivity.
A New Magnesium-Catalyzed Doubly Diastereoselective <i>anti</i>-Aldol Reaction Leads to a Highly Efficient Process for the Total Synthesis of Lactacystin in Quantity
作者:E. J. Corey、Weidong Li、Gregory A. Reichard
DOI:10.1021/ja973444c
日期:1998.3.1
is described for metal-catalyzed doubly diastereoselective Mukaiyama aldolcoupling of a chiral tertiary α-amino aldehyde and an achiral silylenolether to form selectively an anti-aldol product. The metal requirement is strict, since of several salts tested only MgI2 functions as an effective catalyst. The MgI2-catalyzed aldol greatly facilitates the total synthesis of lactacystin (1) and the corresponding