The synthesis of a series of 5,6-monobenzannulated spiroketals is reported. The use of various styrenes in a Kulinkovich reaction with an appropriately functionalized aliphatic ester affords cyclopropanol products which under basic conditions underwent ring opening to form ketone precursors to the spiroketals. Deprotection of the hydroxyl groups and subsequent cyclization afforded monobenzannulated spiroketals related to the core structure of berkelic acid.
本研究报道了一系列 5,6-单苯并环化螺酮的合成。在库林科维奇反应中使用各种
苯乙烯与适当官能化的脂肪族酯进行反应,可得到
环丙醇产物,这些产物在碱性条件下开环,形成螺酮的酮前体。羟基的脱保护和随后的环化反应产生了与贝壳杉烷酸核心结构有关的单苯annulated螺酮。