Diastereoselective Synthesis of 2-Arylmethylene-6-hydroxyspiro[4.5]deca-7-ones via FeCl3·6H2O-Catalyzed Spiroannulation/Hydride Transfer of 6-(5-Arylpent-4-yn-1-yl)-7-oxabicyclo[4.1.0]heptan-2-ols
摘要:
In the presence of a catalytic amount of FeCl3 center dot 6H(2)O, 6-(5-arylpent-4-yn-1-yl)-7-oxabicyclo[4.1.0]heptan-2-ols underwent attack of the pendant acetylene at the iron-activated oxirane to give a vinylic carbocation. Hydride transfer from the carbinol carbon to the newly formed cation center furnished 2-arylmethylene-6-hydroxyspiro[4.5]deca-7-ones in excellent stereoselectivity and good yields.
Diastereoselective Synthesis of 2-Arylmethylene-6-hydroxyspiro[4.5]deca-7-ones via FeCl3·6H2O-Catalyzed Spiroannulation/Hydride Transfer of 6-(5-Arylpent-4-yn-1-yl)-7-oxabicyclo[4.1.0]heptan-2-ols
摘要:
In the presence of a catalytic amount of FeCl3 center dot 6H(2)O, 6-(5-arylpent-4-yn-1-yl)-7-oxabicyclo[4.1.0]heptan-2-ols underwent attack of the pendant acetylene at the iron-activated oxirane to give a vinylic carbocation. Hydride transfer from the carbinol carbon to the newly formed cation center furnished 2-arylmethylene-6-hydroxyspiro[4.5]deca-7-ones in excellent stereoselectivity and good yields.
Facile Synthesis of Spirocyclic Ketones via Gold(I)-Catalyzed Claisen-Type Rearrangement of Cyclic 8-Aryl-2,7-enyn-1-ols
作者:Ming-Chang P. Yeh、Hui-Fen Pai、Chuen-Yo Hsiow、Yan-Rong Wang
DOI:10.1021/om900833k
日期:2010.1.11
The gold(I)-catalyzed Claisen-type rearrangement of cyclic 8-aryl-2,7-enyn-1-ols proceeds via a cationic allylic vinyl ethergold intermediate to give spirocyclic ketones. The reaction proceeded via attack of the hydroxyl group onto the gold-activated alkynes followed by [3,3]-sigmatropic rearrangement to generate the spirocyclic ketones. This transformation can be applied to the synthesis of aza-