
%0 Journal Article
%A Bannon, CD 
%A Eade, RA 
%A James, P 
%A McKenzie, GP 
%A Simes, JJH 
%T Extractives of Australian timbers. XII. Minor sapogenins of <I>Castanospermum australe</I> (Leguminosae). A stereospecific synthesis of methyl 2&#946;,3&#946;-Dihydroxyolean-12-en-28-oate
%J Australian Journal of Chemistry
%D 1973/03/01
%V 26
%N 3
%P 629-639
%K 
%R https://doi.org/10.1071/CH9730629
%U https://www.publish.csiro.au/paper/CH9730629 
%X The sapogenin mixture prepared from the extract of the wood of Castanospermum australe Cunn. &amp; Fras. has been shown to contain the known triterpenes 2&#946;,3&#946;-dihydroxyolean-12-en-28-oic acid and 3&#946;- hydroxyolean-12-ene-23,28-dioic acid; the latter also occurs as the free triterpene. The identity of methyl 2&#946;,3&#946;-dihydroxyolean-12-en-28- oic acid has been established by a high yielding stereospecific synthesis starting from methyl crategolate; this synthesis at the same time confirmed the revised configurations assigned from N.M.R. evidence1 to the hydroxy groups in the two cis-2,3-diols of the isomeric methyl 2,3-dihydroxyolean-12-en-28-oates. The identity of methyl 3&#946;- hydroxyolean-12-ene-23,28-dioate has been established by comparison with a specimen prepared by an unambiguous synthesis from dimethyl medicagenate. 
