Nmr Studies of Colchicine and its Photoisomers, β- and λ-Lumicolchicines

Abstract
Unambiguous 1H- and 13C-nmr assignments of colchicine [1], .beta.-lumicolchicine [3], and .gamma.-lumicolchicine [4] have been obtained using a combination of 1D-and 2D-nmr spectroscopic techniques. The data indicate that .gamma.-lumicolchicine [4] is a stereoisomer of .beta.-lumicolchicine [3] and provide definitive evidence for their stereochemical assignments.