Abstract: The present invention relates to a process for producing bile acid derivatives having a protected hydroxyl group in the 3 position comprising contacting a bile acid derivative having an unprotected 3-alpha-hydroxyl group with a specific lipase. The present invention further relates to a bile acid derivative obtained or obtainable by the process, to the use of the bile acid derivative obtained or obtainable by the process for producing lithocholic acid and also to a process for producing lithocholic acid and to lithocholic obtained by the process. The invention further relates to the use of lithocholic acid obtained or obtainable by the process for producing ursodeoxycholic acid or ursodeoxycholic acid derivatives.