Sodiumhypochlorite pentahydrate (NaOCl·5H2O) can be used toward the efficient glycol cleavage of trans-cyclic glycols, which are generally resistant to this transformation. Interestingly, the reaction of cis-cyclic glycols with NaOCl·5H2O is slower than that observed for the corresponding trans-isomer. This trans selectivity is in sharp contrast to traditional oxidants used for glycol cleavage. Acyclic
Aliphatic C–H activation with aluminium trichloride–acetyl chloride: expanding the scope of the Baddeley reaction for the functionalisation of saturated hydrocarbons
作者:Catherine L. Lyall、Mario Uosis-Martin、John P. Lowe、Mary F. Mahon、G. Dan Pantoş、Simon E. Lewis
DOI:10.1039/c2ob26765a
日期:——
activation and here we demonstrate its applicability to a range of other saturated hydrocarbons. Structural elucidation of the products is described and a mechanistic rationale for their formation is presented. The “aliphatic Friedel–Crafts” procedure allows for production of novel oxygenated building blocks from abundant hydrocarbons and as such can be considered to add significant synthetic value in a single
The chemistry of pentavalent organobismuth reagents
作者:Derek H.R. Barton、Jean-Pierre Finet、William B. Motherwell、Clotilde Pichon
DOI:10.1016/s0040-4020(01)88167-9
日期:1986.1
A catalytic bismuth system (Ph3Bi-NBS-K2CO3-CH3CN with 1% water) for the cleavage of α-glycols is shown to have a different mechanism from the cyclic process observed with the stoichiometric BiV reagents previously studied. The catalytic system cleaves cis- and trans-decalin-9,10-diols at nearly the same rate, whereas the stoichiometric system does not cleave the trans-9,10-diol. Evidence for the insertion
作者:Derek H. R. Barton、William B. Motherwell、Alan Stobie
DOI:10.1039/c39810001232
日期:——
α-Glycols are smoothly cleaved by a catalytic amount of triphenylbismuth in the presence of potassium carbonate and a little water, using N-bromosuccinimide (or another N-bromo-reagent) for the oxidation of BiIII to BiV.
Catalytic, Asymmetric Transannular Aldolizations: Total Synthesis of (+)-Hirsutene
作者:Carley L. Chandler、Benjamin List
DOI:10.1021/ja8024164
日期:2008.5.1
We report an asymmetric, catalytic transannular aldolization that provides polycyclic products useful for natural product synthesis. We found that a proline-derivative catalyzes the transannular aldol reaction of 1,4-cyclooctanediones to the corresponding cyclic beta-hydroxy ketones in good yields and with high enantioselectivities. The utility of our reaction has been demonstrated in a total synthesis