var transactionOptions = new System.Transactions.TransactionOptions();

transactionOptions.IsolationLevel = System.Transactions.IsolationLevel.ReadUncommitted;

using (var transactionScope = new System.Transactions.TransactionScope(System.Transactions.TransactionScopeOption.Required, transactionOptions))

{

    using (var context = new MyEntityConnection())

    {

    }

    transactionScope.Complete();

}

db.Product.Attach(model);

db.Entry(model).State = System.Data.EntityState.Modified;

db.SaveChanges();