The first total synthesis of tanzawaic acid A(GS-1302-3) is described. The stereocontrolled synthetic route allowes the absolute stereochemistry to be determined. One key transformation in the sequence involves a Stille coupling with a highly hindered aryl triflate. Examples and results of several coupling reactions are also included.
SYNTHESIS OF CHIRAL 2-METHYL-3-ALKENOIC ESTERS<i>VIA</i>1,2-REARRANGEMENT OF ALKENYL GROUP
作者:Yutaka Honda、Aiichiro Ori、Gen-ichi Tsuchihashi
DOI:10.1246/cl.1986.13
日期:1986.1.5
Hydrolysis of optically pure 1-alkenyl-2-sulfonyloxy-1-propanone acetals afforded optically and geometrically pure title compounds via stereospecific 1,2-rearrangement of alkenyl group.
A General Synthetic Method of Chiral 2-Arylalkanoic Esters via Thermal 1,2-Rearrangement
作者:Yutaka Honda、Aiichiro Ori、Gen-ichi Tsuchihashi
DOI:10.1246/bcsj.60.1027
日期:1987.3
(S)-1-Aryl-2-sulfonyloxy-1-alkanone acetals, prepared from natural ethyl (S)-lactate or (S)-valine (chiral sources) by the use of a Grignard reaction, were rearranged under hydrolytic conditions in the presence of a base to give (S)-2-arylalkanoic esters which, in general, showed much higher pharmacological activities than their antipodes.
A new reductive 1,2-rearrangement of aryl (or alkenyl) groups of α-sulfonyloxy acetals to give the title compounds was developed by using the combination of i-BU2AlH and Et3Al, and this method was applied to the synthesis of optically pure (R)-(−)-α-curcumene.