+++ SD1 thanks sylvio!!!!!!

[KCN]

Synthesis of 4-aza analog of ramelteon: a novel tricyclic 1,6,7,8-tetrahydro-2H-cyclopentaΔfuro[2,3-b]pyridine derivative as melatonin receptor ligand
Tatsuki Koike , , Yasutaka Hoashi, Takafumi Takai, Osamu Uchikawa
Tetrahedron Letters
Volume 52, Issue 23, 8 June 2011, Pages 3009-3011

DOI:

http://dx.doi.org/10.1016/j.tetlet.2011.03.147

[sylvio]