Ring transformations of heterocyclic compounds. XVIII . Spiro[cyclohexadiene-indolines] with three stereocenters from pyrylium salts and chiral methyleneindolines - an example of a high diastereoselective ring transformation
作者:Thomas Zimmermann、Ulrich Abram
DOI:10.1002/jhet.5570360518
日期:1999.9
perchlorates 2) in the presence of triethylamine/acetic acid in ethanol by a 2,5-[C4+C2] pyrylium ring transformation is reported. Structure elucidation is performed by X-ray structure determinations of the spiro[cyclohexadiene-indolines] 4a, 4p and 4t. The influence of various substituents at C-3 of the methyleneindolines 3 on the stereochemistry of the transformation, mechanistic details as well as spectroscopic
6芳酰基-3,5- diarylspiro [环己-2,4-二烯-1,2'-二氢吲哚]的非对映选择性合成4具有从2,4,6-三芳基高氯酸盐3个立体中心1和手性methyleneindolines 3(产生在原位由相应的3-脱质子ħ -indolium高氯酸盐2由2,5- [C中的三乙胺/乙酸在乙醇存在下)4 + C 2报道]吡喃鎓环转化。通过对螺[环己二烯-二氢吲哚] 4a,4p和4t进行X射线结构测定来进行结构阐明。各种取代基中的C-3的methyleneindolines的影响3上进行改造的立体化学的,机械的细节以及产品4的光谱数据进行了讨论。