36. C45- and C50-Carotenoids Part 81)Synthesis of (all-E,25,2′S)-Bacterioruberin, (all-E,2S,2′S)-Monoanhydrobacterioruberin, (all-E,2S,2′S)Bisanhydrobacterioruberin, (all-E,2R,2′R)-3,-Tetrahydrobisanhydro- bacterioruberin, and (all-E,S)-2-Isopentenyl-3,4-dehydrorhodopin

Article abstract of DOI:10.1002/hlca.19970800212

Starting from (R)-3-hydroxybutyric acid ((R)-10) the C₄₅- and C₅₀-carotenoids (all-E,25,2′S)-bacterioruberin (1), (all-E,2S,2′S)-monoanhydrobacterioruberin (2), (all-E,2S,2′S)-bisanhydrobacterioruberin (3), (all-E,2R,2′R)-3,4,3′,4′-tetrahydrobisanhydrobacterioruberin (5), and (all-E,S)-2-isopentenyl-3-4-dehydrorhodopin (6) were synthesized. By comparison of the chiroptical data of the natural and the synthetic compounds, the (2S)- and (2'S)-configuration of the natural products 1-3 and 6 was established.