Phthalimides, hydroxy synthesis

Karimi, B. Rajabi, J. Efficient aerobic oxidation of acetals to esters catalyzed by N-hydroxy phthalimide and Co(II) under mild conditions. Synthesis 2003, 2373-2377. 

Rearrangements arising by carbonyl hydrogen abstraction are frequently of value in the synthesis of nitrogen-containing heterocycles. The NN-disubstituted /S-keto-amides (133), on irradiation in benzene, are converted into the 4-hydroxy-2-pyrrolidinones (134), presumably by 8-hydrogen abstraction, in yields of up to 88%.107 Further reports of the cyclization of N-substituted phthalimides have been published. Irradiation of a series of TV-alicyclic phthalimides (135) provides a route to the benzazepines (136) via the cyclobutanols (137) 108 the cw-ring junction in the final product was confirmed by independent synthesis. The... 

Two different N-protected hydroxylamines have been used to accomplish the synthesis of these novel hydroxylamine-functionalized resins. fV-Hydroxy-phthalimide has been employed in two ways first, as a nucleophile to splace either a resin-bound chloride ion (30) or a resin-bound mesylate ion (31) Figure 8a) and second, to generate the active phosphonium species required to perform a Mitsunobu reaction on a hydroxyl-functionalized resin (32) (Figure 8b). In both cases, the resin-bound iV-hydroxyphthalimide ester that is generated is subsequently treated with hydrazine to afford resin-bound hydroxylamine. 

Phenylthio)nitromethane is useful in polyoxin synthesis. A ribose nitroalkene (2), derived from (phenylthio)nitromethane and the corresponding aldehyde (93%), was found to react with opposite stereochemical biases with potassium trimethylsilanoate (eq 5) and phthalimide (eq 6) followed by ozonolysis. The hydroxy acid (eq 5) was further transformed into polyoxin C. 

Diazepines have attracted considerable attention in 1980, as befits their commercial importance as antidepressents and in other medicinal applications. Work appeared from Roche describing further investigations into the industrial preparation of the antidepressants, and another group prepared a pyrrolo-benzo[l,4]diazepinone in an analogous manner.Possibly of more interest were two reports on the preparation of 1,3-diazepines which are not so common. Ishikawa et reported the synthesis of (424) by standard methods, and Coyle etal produced (426) by acid-catalysed cyclodehydration of the hydroxy-benzamide (425) in >80% yield. Phthalimide Mannich bases have been widely investigated by several groups in analogous conversions as discussed earlier. 

---