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Template synthesis yields bulk amounts of ladder-shaped molecules SOLID-STATE INTERMOLECstrategy to preorganize moleular synthesis of laddercules that can then be photodianes that provides gram merized to form targeted comamounts of these unusual comZ I P P I N G U P A ladderane template is formed via pounds {Chem. Comm., 2 0 0 3 , pounds in quantitative yields has 1306}. For ladderanes, the temhydrogen bonding when 5-methoxyresorcinol is been developed by assistant plate is formed by cocrystallizing cocrystaltized with a polyene. UV irradiation "zips" the chemistry professor Leonard R. trans-bis(4-pyridyl)polyenes with molecules into a ladder structure. MacGillivray and graduate stu5-methoxyresorcinol.The resordentsTomislav Friscic and the late cinol holds the ends of two poly- realize that the approach worked Xiuchun Gao of the University ene molecules together through perfectly" MacGillivray says. "We of lowa.[Angew. Chem. Int. Ed., 43, hydrogen-bonding interactions. are now focused on pushing the 232(2004)}. method to construct longer ladThe ladderanes are produced Ladderanes feature a series ders and more complex targets." by irradiating powdered samples "The synthesis of the 3- and 5of fused cyclobutane rings that of the templated polyenes with ladderanes is a crowning achievechemists believe could impart UV light for several days. Using unique electronic properties or ment," says chemistry professor N M R spectroscopy to monitor Bruce M. Foxman of Brandeis serve as spacers to separate metals the reaction, the researchers conor functional groups for a potenUniversity "The work provides clude that the polyenes probably tial new class of optoelectronic both a new subclass of solid-state undergo stepwise [2 + 2} cymaterials. Several groups have photocycloaddition products and cloaddition reactions that "zip" made short ladderanes with limitan elegant example of how the the molecules together. Using a ed success, building them up from careful planning and execution of diene and a triene, the Iowa halogenated cyclobutenes, from a solid-state methodology may chemists prepared ladderanes alkenes and alkynes, or by fusing open the door to a simple, highcontaining three and five cytogether polyenes [Angew. Chem. clobutane rings, respectively yield synthesis of an elusive class of Int. Ed., 4 2 , 2822 (2003)]. One molecules."—STEVE RITTER "It was a pleasant surprise to problem, MacGillivray notes, is that in solution the ladder precurPHARMACEUTICALS sors are probably too disorganized to align and react properly The discovery of natural ladderanes in 2002 also has spurred Philip Nadeau, health care industry stock i harmacopeia plans to spin off its drug interest in the molecules. The analyst with S. G. Cowan, says the recent 'discovery operation to stockholders, afnatural compounds have three or progress of PDD collaborations with Bristolter which it will continue in the scientific five fused cyclobutane rings and Myers Squibb and Daiichi in Phase I clinical software business under the name of its curserve as membrane lipids in amtrials may have convinced management that rent software subsidiary, Accelrys. monium-oxidizing bacteria that PDD is ready to stand on its own. CEO Joseph A. Mollica says the spin-off of participate in nitrogen cycling in Last year, Pharmacopeia halted a deal to the Pharmacopeia Drug Discovery (PDD) subthe oceans. The process by which acquire Eos Biotechnology, one of several sidiary will address "difficulties" in Pharmathe bacterial ladderanes are made growth strategies the company considered copeia's current corporate structure by creis still unknown, but it's suspectover the past two years, according to John J. ating two "pure play" companies that can ed that enzymes are involved in a Hanlon, chief financial officer. better focus on objectives and pursue acquiprocess that positions the presitions and investments. Pharmacopeia's Accelrys unit generated cursors via noncovalent bonds, alMark J. Emkjer, Accelrys' president, will revenue of $95.1 million in 2002. PDD revlowing them to react. become CEO of the software company. Mollienue in 2002 reached $29.3 million. PharmaFollowing this cue, MacGilca will serve as CEO of PDD until a successor copeia posted an overall loss of $11.6 million livray's group recently developed is appointed. that year.—RICK MULLIN a template-directed solid-state
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