How do you convert a List of object to a one dimensional array?

I have a list of objects which look like this:

 public class Hub
    {
        public string Stamp { get; set; }
        public string Latency0 { get; set; }
        public string Latency1 { get; set; }
        public string Latency2 { get; set; }
        public string Latency3 { get; set; }
        public string Latency4 { get; set; }
    }

After I convert this list into a Json it looks like the image below.

How can I convert the list into the array shown in the image? Either I should be able to create a C# array which I can further convert into a Json array shown in the image.

I tried using this ToArray() on the list but it only converts it into an array of object.