[azmanam]

Nice.  I thought about a second lactone opening pathway, but saw the 5-endo and went intermolecular.  I didn't think about epoxide 7.

[Honclbrif]

I always screw up the endo/exo thing when it comes to epoxides and was messing around with 4 in acid. I do not know where to hide my face.

Congrats to azmanam on solving this one. I tip my hat, sir.

I must say Dan, this was a fine problem, even though some parts were a serious Payne. I look forward to tackling future POTWs.

[Guitarmaniac86]

This is the kind of thing the post grads do with the lecturers at my uni. Every week we try and crack a synthesis from a paper that has been published. Who ever cracks the synthesis gets to find a paper with an interesting synthesis.

However, I didnt get this at all.