Department of Chemistry, Stony Brook University, Stony Brook, New York 11733, USA.
Org Lett. 2012 Jan 6;14(1):138-41. doi: 10.1021/ol202932x. Epub 2011 Dec 6.
The pseudo C(2) symmetric trans diphenyl oxazoline group acts as an effective chiral auxiliary in the 8π, 6π tandem electrocyclization of a substituted tetraene 1-carboxylic acid. Assignment of absolute stereochemistry to the [4.2.0] bicyclooctadiene product supports a model in which both s-cis and s-trans conformations favor the transition states with the same helical twist. This assignment prefaces the development of analogs of SNF4435 C and D. These natural products demonstrate activity as androgen receptor antagonists and as multidrug resistance (mdr) reversal agents.
伪 C(2)对称反式二苯恶唑啉基团在取代四烯 1-羧酸的 8π,6π 串联电环化中作为有效的手性辅助基。[4.2.0]双环辛二烯产物的绝对立体化学构型的确定支持了这样一种模型,即 s-顺式和 s-反式构象都有利于具有相同螺旋扭转的过渡态。这一分配为 SNF4435 C 和 D 的类似物的开发奠定了基础。这些天然产物表现出作为雄激素受体拮抗剂和多药耐药(mdr)逆转剂的活性。