Synthesis, Isolation, and NMR-Spectroscopic Characterization of Fourteen (Z)-Isomers of Lycopene and of Some Acetylenic Didehydro- and Tetradehydrolycopenes

Article abstract of DOI:10.1002/hlca.19920750611

Eight (Z)-isomers of lycopene were prepared by stereocontrolled syntheses and fully characterized by 1H-NMR, 13C-NMR, mass, and UV/VIS-spectroscopy: (5Z)-, (7Z)-, (15Z)-, (5Z,5'Z)-, (7Z,7'Z)-, (7Z,9Z)-, (9Z,9'Z)-, and (7Z,9Z,7'Z,9'Z)-lycopene.Six additional (Z)-isomers, namely (9Z)-, (13Z)-, (5Z,9'Z)-, (9Z,13'Z)-, (5Z,9Z,5'Z)-, and (5Z,13Z,5'Z)-lycopene, were isolated in small quantities from isomer mixtures by semiprep.HPLC and were identified by 1H-NMR spectroscopy.