Indolylpropionic acid

The possible intramolecular acylation of 3-(3-indolyl)propionic acids as a primary step in a route to the ergoline ring system of the ergot alkaloids has received wide attention (80T3123, 81H(16)267). When the 2-position of the indolylpropionic acid is unsubstituted, intramolecular cyclization to that position occurs (57JCS497). The reaction probably involves... 

The cyclization of 4-cyanomethyl or 4-carbethoxymethyl-substituted 3-indolylpropionic acids 187 by the action of sodium hydride in tetrahy-drofuran leads to 5-substituted l,3,5-trihydrobenzo[c[Pg.35]

The interaction of 1,2-dimethyIindoles 194 (R = H, OMe) with pro-piolactone gives rise to 3-indolylpropionic acids 195 (R = H, OMe) and, on treatment with a mixture of sulfuric and phosphoric acids, only the 5-methoxy-derivative for this series can be transformed into 1,3,4-trihydrobenzo[crf]indole-5-one 196, whereas in the absence of an activating substituent (195, R = H), the cyclization does not take place [53CI(L)823 80LA971]. 

There a number of cases other than those of dihydroxyfumaric acid oxidase and tryptophan oxidase in which peroxidases appear to play the part of oxidases. These include indolylacetic acid oxidase and the related indolylpropionic and indolylbutyric acid oxidases (285, 415,416,618,733,777), the oxidase of oxalic, oxalacetic, ketomalonic, and dihydroxytartaric acids (414), of phenylacetaldehyde (413) and saturated fatty acid oxidase (711). 

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