Cyclization of 4‐Hydroxy‐3‐hydroxyalkylcarbostyrils Under Mitsunobu Conditions
摘要:
Reaction of 4-hydroxy-3-hydroxyalkyl-1-methyl-2(1H)quinolinones with Ph3P/DEAD gives either C- or O-cyclized products depending on chain length. Hydroxyethyl produces only spiro cyclopropylquinolinone 6, whereas hydroxypropyl affords only pyranoquinolinone 8. Hydroxybutyl gives a 2:1 mixture of spiro cyclopentylquinolinone 11 and oxepinoquinolinone 10.