Direct α-allylation of a variety of ketones and aldehydes with 2-allylisourea took place in the presence of a catalytic amount of a palladium(0) complex under neutral and mild conditions. Scope and limitations of this novel method have been investigated.
Synthetic Studies toward Sarain A. Formation of the Western Macrocyclic Ring
作者:Moo Je Sung、Hyoung Ik Lee、Hee Bong Lee、Jin Kun Cha
DOI:10.1021/jo026914g
日期:2003.3.1
Starting with the tricyclic core 2b, annulation to form the 13-membered western ring of sarain A has been achieved to afford the macrocycle 30a by initial construction of the sterically congested quaternary center at C-3, followed by elaboration of the C-3 side-chain and ring-closing olefin metathesis. Also included is a parallel conversion of tricycle 2c to macrocycle 30b containing a functionalized
2-Allylic-substituted isoureas underwent Wittig-type allylidenation of aldehydes in the presence of triphenylphosphine and 2 mol% of [Pd(PPh3)3] to give the corresponding conjugated olefins in tolerable to good yields.