Mechanisms, End of April

Well, its Monday morning and the hoods are down at The Scripps Research Institute. Here's a picture of the lab sitting in the hall, reading papers. I decided it was high time to post the past two week's mechanisms.

 
April 20, 2013:

April 27, 2013:

Answers inside.

April 20, from: Abd Rabo Moustafa, M.M.; Pagenkopf, B.L. Org. Lett. 12, 3168–3171.

April 27, from: Miura, T.; Yadav, N.D.; Iwasaki, H.; Ozeki, M.; Kojima, N.; Yamashita, M. Org. Lett. 14, 6048–6051.