The Couchbase Server is using 127.0.0.1 and not 10.0.2.2.
When the client connects it get the cluster map however that has 127.0.0.1 as the ip address of the node and then the client tries to connect to that address. When you initiated the node if you set the hostname to the correct IP or hostname it should work.
The manual covers this in more details:
http://docs.couchbase.com/couchbase-manual-2.5/cb-install/#using-hostnames