Based on a thread at the Google Code site, some of those using Android 4.2.x on the Google Nexus 4 or the Google Nexus 7 are experiencing a problem with Wi-Fi connectivity on the these devices.
The connection is lost and no syncing is possible. The problem is known as issue 40065.
Starting in November and running to February 1st, there have been complaints about Wi-Fi just cutting off and not working despite normal signal strength.
An XDA forum thread called “Wi-Fi network connectivity issues and a possible fix,” started at the end of 2012 detailed a workaround for the Wi-Fi problem with the Google Nexus 4.