Synthesis of Enantiopure Highly Substituted trans-8a-Hydroxydecahydroisoquinolines by Sequential Diastereoselective IMDA Reaction and Oxanorbornene Nucleophilic Ring Opening
7-endo selenocyclization reactions on chiral 3-prenyl and 3-cinnamyl-2-hydroxymethylperhydro-1,3-benzoxazine derivatives. A way to enantiopure 1,4-oxazepanes
作者:Javier Nieto、Celia Andrés、Alfonso Pérez-Encabo
DOI:10.1039/c5ob01297j
日期:——
A short and efficient procedure for the preparation of a variety of enantiopure 1,4-oxazepanes with up to three stereocenters by 7-endo-cyclization in perhydro-1,3-benzoxazine derivatives is developed.
Regio- and stereoselective 6- exo - trig radical cyclisations onto chiral perhydro-1,3-benzoxazines: synthesis of enantiopure 3-alkylpiperidines
作者:Rafael Pedrosa、Celia Andrés、Juan P Duque-Soladana、Carlos D Rosón
DOI:10.1016/s0957-4166(00)00230-5
日期:2000.7
Enantiopure 3-alkyl substituted piperidines are prepared by diastereoselective 6-exo-trig cyclisation of perhydro-1,3-benzoxazines derived from (-)-(8)-amino menthol. The diastereoselective cyclisation is promoted by tributyltin hydride, and the competitive 1,5-hydrogen migration depends on the position of the acceptor double bond and the radical site. (C) 2000 Elsevier Science Ltd. All rights reserved.