Selective synthesis of epolactaene featuring efficient construction of methyl (Z)-2-iodo-2-butenoate and (2R,3S,4S)-2-trimethylsilyl-2,3-epoxy-4-methyl- gamma-butyrolactone.
[reaction: see text] (+)-Epolactaene was synthesized in 14 steps in the longest linear sequence. The synthesis is highlighted by a highly efficient preparation of the lactone intermediate 4, which only requires three steps from the commercially available (S)-3-butyn-2-ol. It also features a fully stereocontrolled synthesis of the intermediate 9, which was constructed through the use of Zr-catalyzed methylalumination of alkynes and a series of Pd-catalyzed organozinc cross-coupling reactions, such as homopropargylation, direct ethynylation, and alkenylation of the methyl ester of (Z)-alpha-iodocrotonic acid (3).
Tan
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Herbert C. Brown Laboratories of Chemistry, Purdue University, West Lafayette, Indiana 47907-2084, USA.
Negishi
Ei-Ichi
E
D002087:Butyrates / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D004852:Epoxy Compounds / Q000138:chemical synthesis; D007783:Lactones / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010407:Penicillium / Q000737:chemistry; D011090:Polyenes / Q000138:chemical synthesis; D013237:Stereoisomerism; D015040:Zirconium / Q000737:chemistry
D002087:Butyrates; D004852:Epoxy Compounds; D007783:Lactones; D011090:Polyenes; C095351:epolactaene; D015040:Zirconium