using System;

public class Program

{

    public static void Main()

    {

        var c = new Context {Tenant = "Sandbox"};

        Console.WriteLine(c.Tenant);

        Console.WriteLine((c as ContextBase).Tenant);

    }

}

​

public class ContextBase {

    public object Tenant {get;set;} = 5;

}

​

public class Context : ContextBase {

    public new string Tenant {get;set;}

}