Tandem [4+2]/[3+2]-cycloadditions. 2. Asymmetric induction with a chiral vinyl ether
作者:Scott E. Denmark、C.B.W. Senanayake、Ho Ginny-Dai
DOI:10.1016/s0040-4020(01)85599-x
日期:1990.1
A tandem [4+2]/[3+2]-cycloaddition of nitroalkenes tethered to α,β-unsaturated ester dipolarophiles can be effectively triggered with a vinyl ether. Using the chiral vinyl ether 6 as the dienophile, nitroalkenes 1 and 2 undergo highly selective tandemcycloaddition. Hydrogenolytic cleavage of the resulting nitroso acetals produce α-hydroxy lactams (-)-14 and (-)-21 in >98% e.e. with excellent recovery