Carotenoids and related compounds. Part XVI. Structural and synthetic studies on spirilloxanthin, chloroxanthin, spheroidene, and spheroidenone
作者:M. S. Barber、L. M. Jackman、P. S. Manchand、B. C. L. Weedon
DOI:10.1039/j39660002166
日期:——
The structure of spirilloxanthin (rhodoviolascin) was unambiguously determined by degradative and nuclear magnetic resonance spectral studies. Similar studies indicated the structures of chloroxanthin, spheroidene (“Pigment Y”), and spheroidenone (“Pigment R”); these structures have been confirmed by total syntheses.
Carotenoids and related compounds. Part XV. The structure and synthesis of phytoene, phytofluene, ζ-carotene, and neurosporene
作者:J. B. Davis、L. M. Jackman、P. T. Siddons、B. C. L. Weedon
DOI:10.1039/j39660002154
日期:——
Structures have been established for the polyenes, phytoene, phytofluene, ζ-carotene and neurosporene by spectral studies and synthesis. The stereochemistry of these polyenes is discussed.
The total synthesis of 7′,8′-dihydro-γ-carotene (β-zeacarotene) has been accomplished by a WITTIG reaction of 15,15′-dehydro-apo-12′-carotenal(C35) with farnesyltriphenyl-phosphonium bromide.
The photochemical formation of bicyclooctenes b from 12,13-didehydrosqualene (1) upon irradiation at wavelengths longer than 290 nm is reported. The same photoreaction is also observed with trienes 7 and 8 which like 1 have a remote double bond two C-atoms removed from the triene system. A configurational assignment for bicyclooctene 10 obtained from 8 and a mechanism for the observed photochemical