My code with target framework .net 2.0 complies and initializes the auto implemented property in following code where as we can initialize auto implemented properties from C#6 which came in .net version 4.6.
class Program
{
static void Main()
{
Circle cr = new Circle();
Console.WriteLine("Radius=" + cr.Radius);
}
}
class Circle
{
public double Radius
{
get;
set;
} = 12.45; // Initializing Auto Implemented property
}