作者:Hirokazu Tsukamoto、Shogo Hanada、Yumi Nomura、Takayuki Doi
DOI:10.1021/acs.joc.8b01075
日期:2018.8.17
acetal group on a spiro[4,4]nonadiene skeleton. Its total synthesis was achieved by double oxa-Michael addition of 1,8-dihydroxynaphthalene to 2-(1-bromoalkylidene)-4-isopropoxy-4-cyclopentene-1,3-dione, which was prepared by palladium(II)-catalyzed ring expansion of 4-(1-alkynyl)-4-hydroxy-3-isopropoxy-2-cyclobuten-1-one, and a subsequent intramolecular aldol reaction. The synthesis using optically
Spiromamakone A是在螺[4,4]壬二烯骨架上具有萘基乙缩醛基团的外消旋天然产物。通过将1,8-二羟基萘向2-(1-溴代亚烷基)-4-异丙氧基-4-环戊烯-1,3-二酮中加成1,2-二羟基萘的双oxa-Michael加成反应完成合成,该反应是通过钯(II)催化制备的4-(1-炔基)-4-羟基-3-异丙氧基-2-环丁烯-1-酮的环扩环,以及随后的分子内羟醛反应。使用旋光中间体进行的合成能够确定螺索马卡酮A的外消旋步骤,并显示螺索马卡酮A和螺环丙磺舒A是相同的。据报道后者是另一种的构成异构体。