Not really no, but since a company the size of Walmart can get away with (and I know this from recent experience myself purchasing a cellphone service card that sends the code to you in email) sending you digital codes and products "days" after you purchase it, I can see no reason why you can't just send an email to your customers the download or the link after you get the confirmation email of the purchase. Just state this on the site for them so they know ahead of time that it's not automatic. If it can be allowed for Walmart, then why not everyone else.
*goes back to grumbling about Walmarts delivery policies* LOL
On a more serious note though, no you cannot redirect it "persay", but you can redirect to a page on your site that has the download link. The only issue here is that it would be a public page and pretty much anyone can get to it, so that's not a good idea at all really to do that. Always best to do it either with an automated system setup for digital products, or to use the method above that I mentioned and do it manually when you get the orders.
Doing it manually gives you a lot more control also. That way you can utilize the Website Access Manager program by CoffeeCup too and protect those pages from outside downloaders. You can password protect pages and give that password to the purchasers and make it a 24 hour code or 7 hours or whatever so that they only have a small window to download it before the link expires. This keeps them from sharing it with "too many" people in a short time.
In short though, what you are asking for is not a good idea unless it's a system specifically setup for digital downloads that does redirection with protections etc.