
%0 Journal Article
%A Cornforth, J 
%A Hawes, JE 
%A Mallaby, R 
%T A Stereospecific Synthesis of (&#xb1;)-Abscisic Acid
%J Australian Journal of Chemistry
%D 1992/01/01
%V 45
%N 1
%P 179-185
%K 
%R https://doi.org/10.1071/CH9920179
%U https://www.publish.csiro.au/paper/CH9920179 
%X A convenient separation of (E)- and (Z)-3-methylpent-2-enedioic acids was devised, and it was shown that with acetyl chloride or thionyl chloride the (Z)-acid yields the cyclic anhydride while the (E)-acid forms 6-chloro-4-methylpyran-2-one. The chloropyranone by conventional chemistry gave 4-methyl-6-(2&#x2032;-oxopropyl)pyran-2-one which condensed with 4-methylpent-3-en-2-one in the presence of pyrrolidine, yielding 4-methyl-6-(2&#x2032;,6&#x2032;,6&#x2032;-trimethyl-4&#x2032;-oxocyclohex-2&#x2032;-enyl)pyran-2-one. Oxidation with selenium dioxide or t-butyl chromate then gave 6-(1&#x2032;-hydroxy-2&#x2032;,6&#x2032;,6&#x2032;-trimethyl-4&#x2032;-oxotyclohex-2&#x2032;-enyl)-4-methylpyran-2-one, which on reduction by lithium aluminium hydride and reoxidation afforded (&#xb1;)-abscisic acid stereospecifically. 
