Stereoselective synthesis of lissoclinolide and proof that 'tetrenolin' isidentical to lissoclinolide

A 6-step synthesis of the gamma-alkylidenebutenolide lissoclinolide (1; 40% yield) is described. The Z-configured C-1' = C-gamma bond was established by an anti-elimination from dihydroxylactone 10, the trans-configured C-3' = C-2' bond by a Wittig reaction of ylid Z-15 with (tert-butyldiphenylsilyl oxy)acetaldehyde Digressing from this synthesis (Scheme 7), we obtained com pound 2 with the surmised structure of tetrenolin. However, the correct str ucture of 'tetrenolin' turned out to be the same as lissoclinolide. Compoun d 1 exhibited moderate antimiocrobial activity while 2 did not.