Directed and undirected asymmetric dihydroxylation reactions: application in the synthesis of a C-linked analogue of allolactose

Abstract

The complex OsO₄·(S,S)-1,2-diphenyl-N, N′-bis(2,4,6-trimethylbenzyl)ethane-1,2-diamine is an effective reagent for the desymmetrisation of meso-1,2-bis(3,6-dihydro-2H-pyran-2-yl)ethanes by asymmetric dihydroxylation; this process, whose sense of diastereoselectivity depends on substitution and stereochemistry, has been exploited in the synthesis of a C-linked analogue of allolactose.