Tandem Inter [4 + 2]/Intra [3 + 2] Cycloadditions of Nitroalkenes. The Bridged Mode (β-Tether)
作者:Scott E. Denmark、Julie A. Dixon
DOI:10.1021/jo9802168
日期:1998.9.1
A new variation of the tandem inter [4 + 2]/intra [3 + 2] cycloaddition of nitroalkenes has been developed. This method involves the Lewis acid-promoted [4 + 2] cycloaddition of nitro olefins 12 with 1-alkoxy-1,4-dienes 3. The resulting nitronates 13, bearing a C(5) tethered dipolarophile, undergo thermal, intramolecular [3 + 2] cycloaddition to afford stable tricyclic nitroso acetals 14, which can