Synthesis of 2-Azaspiro[4.6]undec-7-enes from <i>N</i>-Tosyl-<i>N</i>-(3-arylpropargyl)-Tethered 3-Methylcyclohex-2-en-1-ols
作者:Ming-Chang P. Yeh、Chia-Jung Liang、Chern-Wei Fan、Wei-Hang Chiu、Jun-Yuan Lo
DOI:10.1021/jo301764g
日期:2012.11.2
The FeCl3-promoted synthesis of 2-azaspiro[4.6]-undec-7-ene rings proceeds via ring expansion/cyclization/chlorination of N-tosyl-N-(3-arylpropargyl)-tethered 6-methylbicyclo[4.1.0]heptan-2-ols. This azaspirocyclic ring skeleton can also be obtained in one pot from the tert-butyldimethylsilyl-protected N-tosyl-N-(3-arylpropargyl)-tethered 3-methylcyclohex-2-en-1-ols and diethylzinc/diiodomethane.
Trifluoromethanesulfonic Acid-Catalyzed Tandem Semi-Pinacol Rearrangement/Alkyne-Aldehyde Metathesis Reaction of Arylpropagylsulfonamide-Tethered 2,3-Epoxycyclohexan-1-ols to Spiropiperidines
作者:Ming-Nan Lin、Shih-Hui Wu、Ming-Chang P. Yeh
DOI:10.1002/adsc.201100576
日期:2011.12
A simple and efficient trifluoromethanesulfonic acid-catalyzed cycloisomerization of arylpropagylsulfonamide-tethered 2,3-epoxycyclohexan-1-ols is described. The cyclization proceeds via tandem semi-pinacol rearrangement/alkyne-aldehyde metathesis to afford spiropiperidines undermild reaction conditions.
Facile Synthesis of Azaspirocycles via Iron Trichloride-Promoted Cyclization/Chlorination of Cyclic 8-Aryl-5-aza-5-tosyl-2-en-7-yn-1-ols
作者:Ming-Chang P. Yeh、Cheng-Wei Fang、Hsin-Hui Lin
DOI:10.1021/ol300434m
日期:2012.4.6
A simple and efficient FeCl3-promoted cyclization/chlorination of cyclic tosylamine-tethered 8-aryl-2-en-7-yn-1-ols was observed. The reaction proceeded instantaneously at 23 degrees C in air to afford (Z)-4-(arylchloromethylene)-substituted azaspirocycles in good to excellent yields. This transformation can also be applied to the synthesis of spirocarbocyclic analogues from cyclic 8-aryl-2-en-7-yn-1-ols and FeCl3.