Synthesis of the Spiroketal Domains of Spirastrellolide

描述（由申请人提供）：螺苯甲素A是一种复杂的海洋天然产物，已被证明是一种高效的蛋白磷酸酶2A抑制剂。就像众所周知的丝氨酸/苏氨酸磷酸酶抑制剂fostriecin和冈田酸一样，螺烯醛可以导致有丝分裂过早进入和有丝分裂停止，因此是一种潜在的治疗多种癌症的药物。然而，关于螺旋藻内酯的实际结构（绝对立体化学和相对立体化学，药效谱等）有许多问题迄今尚未通过分离/降解得到回答，可能通过全合成得到回答。螺旋螺醛内酯的结构复杂性高，因此完全合成需要巨大的努力；我们提出了两个螺旋结构域的立体选择性合成，并进一步提出了一个一般策略，使这两个片段可以结合起来，并完成总合成。

DESCRIPTION (provided by applicant): Spirastrellolide A is a complex marine natural product that has been shown to be a highly potent inhibitor of protein phosphatase 2A. Much like the well-known Ser/Thr phosphatase inhibitors fostriecin and okadaic acid, spirastrellolide causes premature entry into mitosis and mitotic arrest and is thus, a potential theraputic against various forms of cancer. There are however, many questions regarding the actual structure of spirastrellolide (absolute and relative stereochemistries, pharmacaphore etc.) which to date have not been answered through isolation/degredation and could likely be answered by total synthesis. The structural complexity of spirastrellolide is high, so the total synthesis would require a tremendous effort; we are proposing the stereoselective synthesis of the two spiroketal domains, and go on to suggest a general strategy with which the two pieces can be united, and the total synthesis completed.