Hola Pati, I have just done that exercise and I can see where the confusion arises.

The English original was “Such interesting information!” and the hint given was as “Lit: What so interesting information!” not “What information so interesting!” 

I have learned that the “literal” hints given in these written exercises don’t mean that we should ignore how the syntax should be in Spanish, once translated. Hence the correct answer is ¡Qué información tan interesante! The “tan” or “más” always precede the adjective in these constructions, in this case “interesante.” If you search on the lesson linked to this “Exclamatory Sentences in Spanish using Qué” - you will see how this juggling of syntax occurs, and is perfectly normal. It is probably listed in the “all associated grammar lessons” on the final result page of the exercise as well. I have tried to paste it below. Hope it works. Saludos. John

Exclamatory sentence in Spanish: qué + noun + más/tan + adjective