Google Adsense Responsive Ad unit can only be available in Asynchronous type.If want to make Responsive Ad unit from Asynchronous  to synchronous.Here we go I am going give a tutorial to make Google Adsense Responsive Ad unit from asynchronous to synchronous.
Step 1: Make Responsive ad unit in My Ads of Google Adsense and note down  or copy Ad-Client Number and  Ad- Slot Number which will be coded in ad unit.

Step 2: Replace Ad-Slot Number and Ad-client Number in Below code and paste the code in your website.

<script type=”text/javascript”>
google_ad_client = “xxxxxxxxxxx”;
google_ad_slot = “xxxxxxxxx”
<!– tow basic –>
<script type=”text/javascript”