Stereoselective hydrogenation of methylcyclohex-2-ene-1,4-diols used in the synthesis of ampelomins and deoxy-carbasugars
作者:María Eugenia Lagreca、Ignacio Carrera、Gustavo A. Seoane、Margarita Brovetto
DOI:10.1016/j.tetlet.2013.12.036
日期:2014.1
heterogeneous hydrogenation using Adam’s catalyst, where steric hindrance controlled the stereochemical outcome of the process. On the other hand, for homogeneoushydrogenation of similar olefins using Crabtree’s catalyst, coordination with the allylicalcohols allowed for a controlledhydrogen addition from the more hindered face. In this manner two protocols for the hydrogenation of these types of substrates
Enantioselective synthesis of 2,6-dideoxy carbasugars based on a desymmetrizing hydroformylation–carbonyl ene cyclization process
作者:Bernhard Breit、Aurélien Bigot
DOI:10.1039/b817786d
日期:——
A practical one-pot process involving a desymmetrizinghydroformylation with the aid of a chiral catalyst-directinggroup (CDG*), followed by a carbonyl ene cyclization provides a straightforward access to both enantiomers of the resulting cyclohexanediol; further divergent, highly selective and protecting group-free transformations furnish the carbocyclic analogues of four important 2,6-dideoxysugars