JOURNAL OF ORGANIC CHEMISTRY, vol. 63, no. 22, page. 7590 - 7591, 1998-10-30
TETRAHEDRON LETTERS, vol. 39, no. 35, page. 6321 - 6322, 1998-08-27
SYNTHETIC COMMUNICATIONS, vol. 28, no. 8, page. 1387 - 1397, 1998-01