My search for family in Magdeburg (capital of Sachsen-Anhalt) was helped by contacting the local registry and Jewish community. You can probably Google that info and use Google Translate when necessary. These sources below might also help you, although I'm not sure how far back they go. I usually open them in Google Chrome. Please excuse the poor spacing and variety of fonts. I grabbed the info from various emails. If you contact me directly at mjfourn@..., I can also provide you with a screenshot of a list of other German archival sources created by Alex Calzareth. (I welcome other readers to contact me, if they'd like this info). You might also like to join the Facebook Jewish Geneaology SIG.
Good luck with your search.