I get:
$ echo -e \"D\"{a,b,c}\".jpg\\n\"
Da.jpg
Db.jpg
Dc.jpg
Note: The extra spaces before Db and Dc on the 2nd and 3rd line of the outp
Here is a solution using sed
(that builds upon https://stackoverflow.com/a/2003856/8180143):
$ echo -en "" "D"{a..c}".jpg\n" | sed 's/ //'
Da.jpg
Db.jpg
Dc.jpg
This solution has the advantage of working with inputs having spaces, e.g.,
$ echo -en "" "D "{a..c}".jpg\n" | sed 's/ //'
D a.jpg
D b.jpg
D c.jpg