112419-69-9Relevant articles and documents
Stereochemical Control in the Ester Enolate Claisen Rearrangement. 2. Chairlike vs Boatlike Transition-State Selection
Ireland, Robert E.,Wipf, Peter,Xiang, Jia-Ning
, p. 3572 - 3582 (1991)
The preference for chair-and boatlike transition-state geometries in the ester enolate Claisen rearrangement of straight chain, carbocyclic, and heterocyclic propanoates was investigated.A novel stereoelectronic effect in pyranoid and furanoid glycal systems leads to a significant relative stabilisation of the boatlike vs the chairlike TS(excit.).The preferred transition state in six- and five-membered carbocyclic systems is highly dependent on steric factors, as the energy difference between chair-and boatlike TS(excit.) tends to be small.With straight-chain substrates, a significant contribution of the boatlike TS(excit.) to the rearrangement product mixture is only expected in bis-donor substituted allylic esters.
The convergent synthesis of polyether ionophore antibiotics: The synthesis of the A ring carbamonensin spiro ether
Ireland,Maienfisch
, p. 640 - 651 (2007/10/02)
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