IRON COMPLEXES IN ACYCLIC POLYENE SYNTHESIS

白三烯(LT‘s)是一种脂类代谢产物，起到支气管和 血管紧张剂和已知可增加血管通透性。 研究结果表明，对体内形成的抑制物 白三烯可能在治疗慢性粒细胞白血病中有治疗价值 支气管哮喘和过敏反应。由于自然条件较低 丰富的LT，只有合成的可用的 白三烯和白三烯衍生物将允许未来 生物作用和新陈代谢的机理研究 这些重要的生物分子。 白三烯结构提出了两个合成挑战-- 顺式-二乙烯甲烷官能团及其立体专一性 介绍了烯丙基氧的官能团。新型合成材料 将制定应对这两个挑战的方法 利用1)方便的准备、解决和 手性(二烯)铁阳离子与亲核试剂的反应性 买得起反式，顺-1，3-二烯。由于共轭三烯部分 已知对白三烯结构极为敏感 对空气氧化，多烯的络合保护作用 去铁将是一个巨大的优势在准备和 处理这些敏感化合物。 一类新兴的抗生素是多烯大环内酯类。 这些化合物以共轭多烯链段为特征。 (4-7个双频带)以及最多包含 四个相邻的手性中心。新的综合方法学将是 为这些中心的不对称合成而开发，利用 一种最初的前手性二烯。这将通过以下方式实现 与立体化学导向铁(三羰基)的络合作用 助教。

Leukotrienes (LT's) are lipid metabolites which act as broncho and vasoconstrictors and are known to increase vascular permeability. Findings indicate that inhibitors toward the in vivo formation of leukotrienes could be of therapeutic value in the treatment of bronchial asthma and allergic reactions. Due to the low natural abundance of the LT's, only the availability of synthetic leukotrienes and leukotriene derivatives will permit future mechanistic studies of the biological action and metabolism of these important bio-molecules. The leukotriene structure presents two synthetic challenges--the cis-divinylmethane functionality and the stereospecific introduction of allylic oxygen functionality. New synthetic methodology will be developed to address these two challenges by taking advantage of 1) the facile preparation, resolution, and reactivity of chiral (diene) iron cations with nucleophiles to afford trans,cis-1,3-dienes. Since the conjugated triene portion of the leukotriene structure is known to be extremely susceptible to air oxidation, the "protection" of the polyene by complexation to iron will be a tremendous advantage in the preparation and handling of these sensitive compounds. A growing new class of antibiotics are the polyene macrolides. These compounds are characterized by a conjugated polyene segment (4-7 double bands) as well as adjacent segments containing up to four contiguous chiral centers. New synthetic methodology will be developed for the asymmetric synthesis of these centers utilizing an originally prochiral diene. This will be accomplished through complexation to the stereochemically directing iron(tricarbonyl) adjunct.