One of the most common challenges I hear from students when writing the literature review is synthesizing research material. According to Merriam-Webster, synthesis refers to the composition or combination of parts or elements to form a whole. So, when you synthesize research on your topic, you should be bringing together elements of the research to make points about the research in relation to your study and, specifically, your research problem.
The most fundamental level to make and support points is at the paragraph level. In this sense, synthesizing material for the literature review is like writing a well-structured paragraph generally. The main difference is that for your literature review the topic involves core aspects related to your study.
For the literature review, you will also need to synthesize material involving specific information from the studies you are reviewing. So, it is sometimes helpful to extract the key information from the studies before you start drafting the literature review. Key information includes the research approach and design, purpose, setting, participants, and study findings. Synthesizing material for your literature review would look very much like the example above with the details and specifics of studies relevant to your topic included to make your points. It is also important that you note where study findings converge and diverge. Lastly, it can be helpful to look at previous approved dissertations from your school to see how previous researchers have approached and organized the literature review.