Claisen-rearrangement-mediated ring contraction of macrocyclic lactones
作者:Raymond L. Funk、Matthew M. Abelman、John D. Munger
DOI:10.1016/s0040-4020(01)90572-1
日期:——
Macrocyclic ketene acetals 3 undergo Claisenrearrangements smoothly and constitute a viable and general approach to hetero- or carbocyclic ring systems 4. This novel ring contraction process is subject to high internal asymmetric induction (cf. lactones 7 → carbocycles 8) as well as relative asymmetric induction in the rearrangements of ketene acetals derived from lactones 18, 23 and 27. Finally,
Ru-catalyzed cycloisomerization of a 1,3-diene and the alkene of an N-dienyl-2-vinylaniline substrate proceeded smoothly, leading to a 3-exomethylene-2-vinylindole derivative in good yield. This useful synthon was successfully applied to the total synthesis of (±)-cinchonaminone.