124381-91-5Relevant academic research and scientific papers
Organoaluiminum-promoted claisen rearrangement of allyl vinyl ethers
Nonshita, Katsumasa,Banno, Hiroshi,Maruoka, Keiji,Yamamoto, Hishashi
, p. 316 - 322 (2007/10/02)
Unprecedentad stereochemical control has achieved in the Claisen of allyl vinyl of type 4 with certain bulky organoaluminum Thus, methylaluminum bis(4-bromo-2,6-di-tert-butylphenoxide) (reagent A) can be utilized for obtaining the (Z) isomer, (Z)-6, whereas the (E) isomer, (E)-6 was produced with methylaluminum bis(2,6-diphenylphenoxide) (reagent B). This organoaluminum-promoted Claisen rearrangement proceeds under very mild conditions with very good E and Z selectlvities. On the basis of the Claisen rearrangement of optically active substrate 7 with reagent A, the Z selectivity would be interpreted by the intervention of the chairlike transition-state conformation with the isobutyl substituent axial. The present organoalunminum-promoted Claisen rearrangement has successfully applied to the synthesis of (4E,7Z)-4,7-tridecadienyl acetate (15), a component of the sex of tuberworm moth, in stereoselective fashion. Furthermore, the Claisen rearrangement of bisallyl vinyi ether16 with reagent A or B has been found to involve the more substituted allylic system to furnish dienal 18 preferentially, not obtainable in the ordinary thermal rearrangement. This chemistry been further extended to the ionic rearrangement of dienyl vinyl ether 28 by using reagent A in a polar solvent the previously unknown, remote transfer of the vinyloxy moiety by [3,5]-sigmatropic rearrangement via ionic intermediate 29 has observed.
