From Sugar Lactones to Stereodefined γ-Alkylidenebutenolides – Synthesis of Analogs of the γ-Alkylidenebutenolide Antibiotics Lissoclinolide and Tetrenolin

✍ Scribed by Felix Christian Görth; Andreas Umland; Reinhard Brückner

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 617 KB
• Volume: 1998
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(199806)1998:6<1055::aid-ejoc1055>3.0.co;2-m

✦ Synopsis

A novel strategy for the stereoselective synthesis of E-or Zconfigured γ-alkylidenebutenolides was applied to the preparation of the model compounds 6/7 (E) and 8/9 (Z) of the antibiotics tetrenolin (E) and lissoclinolide (Z), respectively. For introducing the α-substituents of the target molecules the butenolide triflates ul-and lk-16 were subjected to Stille couplings with trans-Bu 3 Sn-CH=CH-

The Beilstein database lists 1600 γ-alkylidene-α,β-unsaturated γ-lactones of substitution pattern 1 ("γ-alkylidenebutenolides"; Scheme 1). Many of them are natural products, some are physiologically active, and several are accessible through laboratory synthesis. [1] The structural complexity of γ-alkylidenebutenolides varies between core structure 2, which is the antibiotic protoanemonin, [2] and uriolide, which is an algal C 40 pigment. [3] "Medium-sized" γ-alkylidenebutenolides include the inhibitor of cholesterol biosynthesis dihydroxerulin (3 [4] ) and the antibiotics tetrenolin (4 [5] ) and lissoclinolide (5 [6] ).