Stereoselective Synthesis of 8,12-Furanoeudesmanes from Santonin. Absolute Stereochemistry of Natural Furanoeudesma-1,3-diene and Tubipofurane
作者:Gonzalo Blay、Luz Cardona、Begoña García、José R. Pedro、Juan J. Sánchez
DOI:10.1021/jo9521458
日期:1996.1.1
Ketobutenolide 3, easily obtained from santonin (1), has been transformed into two natural furanoeudesmanes 4 and 5, isolated from Commiphora molmol and Tubipora musica, respectively. trans- And cis-decalin systems were obtained by stereoselective reduction of the C(4)-C(5) double bond in 3 in the following way: hydrogenation of 3 over Pd/C followed by acidic treatment gave the cis isomer 10 as the
容易从桑通宁(1)中获得的酮丁烯内酯3已被转化为分别从molmiphora molmol和Tubipora musica分离出的两种天然呋喃呋喃二烯醚4和5。反式和顺式十氢化萘系统是通过以下方式立体选择性还原C(4)-C(5)双键在3中的方式:在Pd / C上氢化3,然后进行酸性处理,得到顺式异构体10主要产品 用威尔金森氏催化剂对C(1)-C(2)双键进行选择性氢化,然后用NaTeH还原,主要得到反式异构体9。化合物9和10以平行顺序转化为4和5。合成产物的旋光度和CD测量表明,两种天然产物的立体化学都应修改为对映体形式。