English: The picture shown is for the Johnson synthesis.
Johnson, W. S., Graber, R. P. (July 1948). "BIS-DEHYDRODOISYNOLIC ACID". Journal of the American Chemical Society. 70 (7): 2612–2613. doi:10.1021/ja01187a525.
William S Johnson & Robert P Graber, US2574396 (1951 to Individual).
William S Johnson & Robert P Graber, US2683738 (1954 to Individual).
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