Rapid Construction of the Aza-Propellane Core of Acutumine via a Photochemical [2 + 2] Cycloaddition Reaction
摘要:
Synthetic efforts toward the chlorinated aza-propellane alkaloid acutumine (1) are described. The key vicinal quaternary centers were constructed by a photochemical [2 + 2] cycloaddition reaction of a furanyl-tetrahydroindolone. Dihydroxylation of the [2 + 2] product enabled a tandem retroaldol/intramolecular ketalization reaction, which revealed the aza-propellane core of 1 while generating an unusual, caged, pentacyclic hemiketal product.
Furan-Terminated <i>N</i>-Acyliminium Ion Initiated Cyclizations in Alkaloid Synthesis
作者:Steven P. Tanis、Melissa V. Deaton、Lisa A. Dixon、Mark C. McMills、Jeffrey W. Raggon、Mark A. Collins
DOI:10.1021/jo980718l
日期:1998.10.1
cyclizations for the synthesis of linearly fused alkaloid precursors (Figure 2) is presented. The outcome of the cyclization event depends on the position of furan tether attachment (2 vs 3), tether length, and furan 5-substituent (R = H, CH(3), Ar). 3-Substitutedfurans cyclized to form 6- and 7-membered ring containing furans 35-38, 50, and 51 in good to excellent yields. 2-Substituted furans closed to form
Rapid Construction of the Aza-Propellane Core of Acutumine via a Photochemical [2 + 2] Cycloaddition Reaction
作者:Raul Navarro、Sarah E. Reisman
DOI:10.1021/ol3017963
日期:2012.9.7
Synthetic efforts toward the chlorinated aza-propellane alkaloid acutumine (1) are described. The key vicinal quaternary centers were constructed by a photochemical [2 + 2] cycloaddition reaction of a furanyl-tetrahydroindolone. Dihydroxylation of the [2 + 2] product enabled a tandem retroaldol/intramolecular ketalization reaction, which revealed the aza-propellane core of 1 while generating an unusual, caged, pentacyclic hemiketal product.