According to Google Translate the phrase is pronounced dōshite (I've also heard it pronounced like that in anime and movies).
I couldn't help noticing that the う (u) isn't being pronounced. Why is this?
When う follows a character ending in the "o" sound it extends that sound. The "u" is pronounced, but as "o" instead. I recommend listening to examples.
The same thing also happens with い and characters that end with an "e" sound. (Eg. せんせい). The い serves to extend the "e" sound.
It is also extremely crucial to include that extension in both writing and speaking because having it or not having it will change the meaning completely. For example:
high school while