How to sync apps from one itunes account to another?

I have a bunch of apps on my iPhone, that I have used various Apple ID's to download, and I want to make one iTunes account, with these apps. Can I do that? And just have one email and password to put in to update them?

You can't. Obviously that would be like piracy allowing that.

You unfortunately can't. When you purchase an app the app is linked to your account. This is to prevent piracy.

You could find the apps that are free and download them again though.