Partial Synthesis and Characterization of Capsokarpoxanthins and 3,6-Epoxycapsanthins

Article abstract of DOI:10.1002/hlca.19980810535

The acid-catalyzed hydrolysis of (3S,5R,6S,3′S,5′R)-5,6-epoxycapsanthin (5) led to (3S,5R,6R,3′S,5′R)- (7) and (3S,5R,6S,3′S,5′R)-capsokarpoxanthin (8). In addition, (3S,5R,8R,3′S,5′R)- (9), (3S,5R,8S,3′S,5′R)-capsochrome (10), and (3S,5R,6R,3′S,5′R)-3,6-epoxycapsanthin (11) were obtained. The acid-catalyzed hydrolysis of (35,55,6R,3′S,5′R)-5,6-epoxycapsanthin (6) afforded (3S,5S,6R,3′S,5′R)-capsokarpoxanthin (12), (3S,5S,8S,3′S,5′R)- (13) and (3S,5S,8R,3′S,5′S)-capsochrome (14) as well as (3S,5S,6R,3′S,5′R)-3,6-epoxyepicapsanthin (15). Compounds 5-15 were isolated in crystalline form and characterized by their UV/VIS, CD, ¹H- and ¹³C-NMR, and mass spectra.