TETRAHEDRON LETTERS, vol. 51, no. 42, page. 5581 - 5584, 2010-10-20
JOURNAL OF ORGANIC CHEMISTRY, vol. 74, no. 24, page. 9543 - 9545, 2009-12-18
TETRAHEDRON LETTERS, vol. 45, no. 24, page. 4607 - 4610, 2004-06-07