3-Hydroxy-3- -isoindolin-1 -ones

The reductive coupling of phthalimides with ketones and aldehydes in THF by low-valent titanium generated from Zn-TiC gave 3-hydroxy-3-(l-hydroxyaIkyl)-isoindolin-l-ones as two-electron reduced products and alkyhdene-isoindolin-l-ones as four-electron reduced products. These could be obtained selectively by controlling the reaction conditions. The geometric ratios of the alkylideneisoindolin-l-ones obtained from phthalimides and aldehydes could be increased by reflux in PPTS/ toluene (catalyst). In particular, the Z-isomers of A-unsubstituted alkylideneisoindolin-l-ones could be obtained exclusively. 

An aq. soln. of 2-bromo-N-ethyl-4 -hydroxybenzanilide, NaOH, and NaBH4 irradiated 1.25 hrs. with a 100 w. high-pressure Hg-lamp 2 -ethyl-4-hydroxy-spiro(cyclohexa-2,5-diene-l,l -isoindolin)-3 -one. Y 62% based on startg. m. consumed. Z. Horii et al., Chem. Commun. 1970, 1039. 

Spirocyclohexadienes, rearrangement 27, 911 Spiro(cyclohexa-2,5-dien-l,l -isoindolin)-3 -ones, 4-hydroxy-27, 862... 

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