Today's Org. Lett. ASAPs had this gem.
Things like this piss me off a bit but mostly confuse me. At first blush everything seems fine, they even clarify that the mechanism is proposed. Step one is a straightforward sequence of additions which is (probably) inaccurately described as a Diels-Alder, but the second step is pretty interesting. It includes the addition of a nucleophile to a tertiary carbinol under basic conditions. I can think of a couple of reasonable mechanisms that lead to the drawn product, but they aren't immediately obvious. In fact the one I like best doesn't even use that particular intermediate. In any case it seems to me to be a significant intellectual leap to the final product, and the authors a) don't actually know what's going on, b) think that it's the direct displacement of the carbinol, or c) know what is going on, but can't be bothered to describe it, even though they wrote the scheme in the first place.
None of those options is particularly satisfying, and these types of half baked situations always remind me of the South Park episode with the underpants gnomes and their business plan.