Double intramolecular Diels–Alder reaction of α,β-unsaturated hydrazones: a new route to 2,2′-bipyridines
作者:Nicholas Bushby、Christopher J. Moody、Christopher J. Moody、David A. Riddick、Ian R. Waldron
DOI:10.1039/a901641d
日期:——
Heating the 1,3-diynyl bis-α,β-unsaturated hydrazones 3, 6 and 10 results in double intramolecular DielsâAlder reaction of the 1-azadienes, and after aromatisation by loss of dimethylamine, the formation of bipyridines 11â14.
Double intramolecular hetero Diels–Alder reactions of α,β-unsaturated hydrazones as 1-azadienes: a new route to 2,2′-bipyridines
作者:Nicholas Bushby、Christopher J. Moody、David A. Riddick、Ian R. Waldron
DOI:10.1039/b105409k
日期:——
Salicylaldehyde was converted into the O-propynyl- and O-butynyl α,β-unsaturated aldehydes 4 and ketones 6, subsequent reaction of which with N,N-dimethylhydrazine and alkyne homocoupling gave the 1,3-diyne bis(hydrazones) 8, substrates for a double intramolecular hetero Diels–Alderreaction. Similar substrates 11, 15a/15c and 15b/15d were prepared from 2-(N-benzoylamino)cinnamaldehyde, hex-5-ynol and hept-6-ynol
Efficient One-Step Synthesis of Bis-Spiroketals from Diynediols by π-Lewis Acid-Catalyzed Hydroalkoxylation/Hydration
作者:Ivan Volchkov、Kamlesh Sharma、Eun Jin Cho、Daesung Lee
DOI:10.1002/asia.201100131
日期:2011.8.1
Spiroling out of control: An efficientone‐stepsynthesis of 5‐5‐5, 5‐5‐6, and 6‐5‐6 bis‐spiroketals from 4,6‐diyne‐1,n‐diols and 5,7‐diyne‐1,n‐diols has been developed with good yields. A mixture of cis‐ and trans‐bis‐spiroketals were generally obtained from each substrate and the isolated cis‐ and trans‐bis‐spiroketals undergo interconversion to reach their equilibrium composition (see scheme).