jo9802168_si_001.pdf (782.42 kB)
Tandem Inter [4 + 2]/Intra [3 + 2] Cycloadditions of Nitroalkenes. The Bridged Mode (β-Tether)†
journal contribution
posted on 1998-08-21, 00:00 authored by Scott E. Denmark, Julie A. DixonA 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 be subsequently reduced to unveil a new carbocycle 16. Thus, in three steps, highly
functionalized aminocyclopentanes can be stereoselectively constructed in high yield.