NEWS OFTHE WEEK
TEXAS UTILITY GOES GREEN BUYOUT: TXU deal may lead to cleaner electricity generation plan
With 18,300 MW of generation, TXU is Texas' largest retail electricity provider.
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I HE LARGE Texas-based electric utility TXU has agreed to trim back a controversial plan to con struct 11 new coal-fired power plants in the state and also to implement several "green" initiatives. These actions are part of a buyout agreement with an investor consortium led by Kohlberg Kravis Roberts & Co., Texas D Pacific Group, and Goldman Sachs * Group. The deal includes terms negotiated with several national environmental groups. The investors will spend $45 billion to acquire TXU, and if the deal goes through, it will mark the largest ever leveraged private equity buyout. Still to come, how ever, is approval by stockholders and regulators, as well as the pos sibility that other bidders may
PALAU'AMINE RECONSIDERED SPONGE ALKALOIDS: Structural revisions rankle chemists
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HE COMPLEX natural product palau'amine purportedly has beneficial biological effects, but these days it's giving some chemists a big head ache. Following structural studies of the molecule's chemical cousins, three research groups report that the structures of palau'amine and all the marine natural products in its family probably need to be revised. Any structural revision of palau'amine is sure to vex the pack of top organic synthesis groups that have been racing to complete the first total synthesis of the molecule. "Depending upon the synthetic approach being pursued, this structural revi sion, if correct, could represent a significant setback for groups engaged in its total syn thesis," comments Larry E. Overman of the University of California, Irvine. In their efforts to suss out the structure of some palau'amine congeners, teams led by natural products chemists Matthias Kôck of Germany's Alfred Wegener Institute, Ronald Palau'amine revised J. Quinn of Australia's Griffith University, WWW.CEN-0NLINE.ORG
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seek to purchase the utility before the deal goes final 50 days from the Feb. 26 agreement. TXU had planned to construct some 9,000 MW of new coal-fired power-plant capacity, and the company enjoyed the support of the Texas governor and others. But that proposal drew firm opposition from a mix of residents, environmental groups, and state pension fund administrators who promised to use shareholder resolutions to challenge the costs, environmental im pact, and long-term financial consequences of building new coal plants in a greenhouse-gas-constrained world. Growing opposition along with permit delays, diffi culty in moving sufficient amounts of coal to Texas, and possible construction workforce shortages led TXU to consider and finally accept the buyout offer, says Kim Morgan, a TXU spokeswoman. "This investor group brings a knowledge base, skill set, and technical exper tise that just made the most sense for us," she adds. TXU still plans to build three coal plants. To meet future consumer electricity needs, TXU also has com mitted to spend $400 million for efficiency and conser vation efforts to reduce demand, double its purchase of wind energy to 1,500 MW, and move toward greater use of natural gas to generate electricity. TXU also announced its intention to join a clean-coaltechnology consortium and will explore siting a coalgasification power plant in the state.—JEFF JOHNSON
and Shigeki Matsunaga of the University of Tokyo independently found the same stereochemical discrepancies between palau'amine and their newly isolated structures (Angew. Chem. Int. Ed., DOI: 10.1002/ anie.200604076; J. Org. Chem., DOI: 10.1021/J0062007; Tetrahedron Lett. 2007,48,2127). These researchers suggest that the configuration originally assigned to the molecule's chlorinated carbon is incorrect and that the junction of two five-membered rings at the molecule's core is in a trans configuration, not cis. It's unusual to find trans-fused five-membered rings in organic compounds, particularly natural products, Kôck notes. When his group first suggested the revised structure, he says, "no one believed us." To date, no one has reported X-ray analysis of palau'amine or any of its relatives. Chemists don't know the molecule's absolute stereochemistry and can only report its relative configuration. Furthermore, palau'amine aficionados say initial reports of the molecule's promising biological activity haven't panned out. On the bright side, the revised structure jibes with the current thinking on its biosynthetic pathway, according to Phil S. Baran of Scripps Research Institute. Baran also notes that revising palau'amine's structure doesn't detract from "what chemists can learn fundamentally from making these molecules." Kôck also sees a silver lining: "Usually, the synthetic groups tell the natural products chemists that they're wrong," he says. "It's good that this time we could correct ourselves."—BETHANY HALFORD
MARCH 5, 2007
