Elusive 6-<i>e</i><i>xo</i>-Hydroxybicyclo[2.2.2]octan-2-ones from the Corresponding Acetates by Methanolysis in the Presence of CH<sub>3</sub>ONa/La(OTf)<sub>3</sub>
作者:Stefano Di Stefano、Francesca Leonelli、Barbara Garofalo、Luigi Mandolini、Rinaldo Marini Bettolo、Luisa Maria Migneco
DOI:10.1021/ol026326p
日期:2002.8.1
text] A series of 6-exo-acetoxybicyclo[2.2.2]octan-2-ones were converted into the corresponding 6-exo-hydroxybicyclo[2.2.2]octan-2-ones by methanolysis in the presence of CH(3)ONa/La(OTf)(3). Under the given conditions, epimerization at C(6) of the latter led in the least favorable cases only to traces of the more stable 6-endo-hydroxybicyclo[2.2.2]octan-2-ones. This procedure, when combined with the
[反应:见正文]在甲醇存在下,通过甲醇分解,将一系列的6-外-乙酰氧基双环[2.2.2] octan-2-one转化为相应的6-外-羟基双环[2.2.2] octan-2-one。 CH(3)ONa / La(OTf)(3)。在给定的条件下,在最不利的情况下后者的C(6)的差向异构仅导致痕量更稳定的6-内-羟基双环[2.2.2] octan-2-ones。该方法与所描述的将容易获得的6-内-羟基双环[2.2.2]辛烷-2-酮转化为相应的6--外-乙酰氧基衍生物相结合,可提供一种难以实现的6--外-羟基双环[2.2]的途径。 .2] octan-2-ones。显示并设想了对全合成的应用。