Locked Nucleosides Based on Oxabicyclo[3.2.1]octane and Oxabicyclo[2.2.1]heptane Skeletons
作者:Ramprasad Ghosh、Joy Krishna Maity、Basudeb Achari、Sukhendu B Mandal
DOI:10.1021/jo100194z
日期:2010.4.2
oxabicyclo[3.2.1]octane and oxabicyclo[2.2.1]heptane rings in three steps. An oxabicyclo[3.2.1]octane ring compound could alternatively be formed by RCM reaction between C-1−allyl and C-4−vinyl moieties and transformed to nucleoside analogues through a nucleophilic substitution reaction. Participation of a neighboring benzyl ether substituent in one case paved the way for an enantiodivergent synthesis.
d-葡萄糖衍生的底物上的分子内硝酮环加成(INC)反应在C-1处带有烯丙基,在C-5处带有烯键-硝基或在C-1处带有醛-硝基和在C-4带有乙烯基,提供了三环[6.2.1.0 2,6 ]十一烷或三环[5.2.1.0 2,6 ]癸烷环结构。这些三环与氧杂双环[3.2.1]辛烷和氧杂双环[2.2.1]庚烷环经三步转化为双环核苷。氧杂双环[3.2.1]辛烷环化合物也可以通过C-1-烯丙基和C-4-乙烯基之间的RCM反应形成,并通过亲核取代反应转化为核苷类似物。在一种情况下,相邻的苄基醚取代基的参与为对映发散的合成铺平了道路。