Relationship 1x1 (or not)

I have 2 entities:

Product Order and Product ...

Using the fluent API as I say to my entity Requested Item that it has a Product?

Note: The product entity can not have dependencies, although 1 product can be in several items. I do not want it to depend on an item. Request to exist ...

Product Class:

namespace DTO
{
    public class ProdutoDTO
    {
        public int produtoID { get; set; }
        public int codigo { get; set; }
        public string descricao { get; set; }
        public decimal preco { get; set; }
    }
}

Order Item Class:

namespace DTO
{
    public class ItemPedidoDTO
    {
        public int itemPedidoID { get; set; }
        public int quantidade { get; set; }
        public int porcentagemDesconto { get; set; }

        public int produdoID { get; set; }
        public virtual ProdutoDTO produto { get; set; }
    }
}