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Santonin and Related Compounds. VII. Diketo Acids from Tetrahydrosantonins AKIRA TAHARA Received December bo, 1955
The CY- and r-diketo acids ( I I I a and IIIb), prepared bv oxidation from the CY- and r-tetrahydrosantonins (Ia and I b ) respectively, were reacted with various reagents, and on the hssis of the results of these reactions, the proposed structures (Ia and Ib) for the tetrahydrosantonins have been discussed. CH3
In the previous paper of this series,’ the configurational structures I a and I b were proposed, respectively, for a- and y-tetrahydrosantonins, prepared from a-santonin by catalytic hydrogenation.
-+
@THcH3 CH,
0-co
CHc
CHCH3
C H 3 0 H COOH I1 a. b ic, d)
I a, b, c, d
i
q, CH: