Yamaguchi-type lactonization as a key step in the synthesis of marine metabolites: (+)-luffalactone.

A Yamaguchi-type cyclization of 5 and subsequent photochemical oxidation of the furanic ring are the key steps in the first synthesis of the marine metabolite (+)-luffalactone 4 and its epimer at C-16, 16-epi-luffalactone, 27. With this work, we have successfully established the absolute configuration of the natural product. The key intermediate 5 was obtained from the easily accessible diacetate 6a/6b.