Ammonium directed dihydroxylation of N,N-dibenzylaminocyclohex-2-ene: metal-free syntheses of the diastereoisomers of 3-dibenzylamino-1,2-dihydroxycyclohexane

摘要

Treatment of N,N-dibenzylaminocyclohex-2-ene with mCPBA in the presence of CCl_3CO_2H gives l,2-anti-2,3-syn-l-trich]oro-acetoxy-2-hydroxy-3-N,N-dibenzylaminocyclohexane with high diastereoselectivity; this methodology has been used to facilitate the metal-free stereoselective syntheses of all the diastereoisomers of 3-dibenzylamino-l,2-dihydroxycyclohexane.The epoxidation of allylic alcohols is a widely studied synthetic transformation in organic chemistry,with the tartrate directed asymmetric epoxidation by Sharpless el al.arguably the most valuable synthetic protocol developed within this area.