RESUMEN
A 2 : 1 mixture of NCS and Ph(3)P successfully promoted the anti-dichlorination of olefins to provide corresponding dichlorides, serving as a molecular chlorine surrogate generated in situ.
Asunto(s)
Alquenos/química , Hidrocarburos Clorados/síntesis química , Organofosfatos/química , Tiocianatos/química , Hidrocarburos Clorados/química , Estructura MolecularRESUMEN
The alkylation of dienolates generated from 3-methoxycycloalk-2-enones having a 3'-hydroxyl alkenyl chain provides the corresponding quaternized cycloalkenones in a highly diastereoselective manner. The high degree of stereocontrol in the α-quaternization possibly implies intervention of a rigid chelating transition state that allows an efficient 1,4-asymmetric induction to take place.
Asunto(s)
Técnicas de Química Sintética/métodos , Hidrocarburos Alicíclicos/química , Alquilación , Hidrocarburos Alicíclicos/síntesis química , Estructura Molecular , EstereoisomerismoRESUMEN
A stereoconvergent access to chiral carbocyclic building blocks is reported. 6-(3'-Hydroxy-4'-methylpent-4'-enyl)-3-methoxy cyclohex-2-enone () that consists of four stereoisomers, i.e., racemic ca. 1 : 1 diastereomers, is converted to enantiomerically pure carbocycles through a combination of regioselective catalytic asymmetric reduction and alkylative remote stereoinduction. The present stereoconvergent strategy has allowed the formal synthesis of bioactive (-)-dysidiolide.