Highly Efficient Stereocontrolled Total Synthesis of the Polyfunctional Carotenoid Peridinin

Abstract

The convergent, highly stereoselective synthesis of the nor carotenoid peridinin (1) is based on the following key steps: a) a Sharpless asymmetric epoxidation, b) reaction with a silylfuran‐Wittig reagent and oxidation with 1O2, c) a Pd‐catalyzed three‐step one‐pot procedure for the formation of the ylidene butenolide segment), and d) a modified Julia olefination. This provides a new method for the synthesis of carotenoids.

First Total Synthesis of Cucurbitaxanthin A Applying Regioselective Ring Opening of Tetrasubstituted Epoxides

“…As shown in Chart 4, epoxides 6e and 6f were prepared from the known C 10 -epoxy aldehyde 12, which was recently synthesized by Katsumura's group 10) via a Sharpless asymmetric epoxidation of the corresponding allylic alcohol derived from the optically active hydroxyketone 11.…”

Sesquiterpene-like inhibitors of a 9-cis-epoxycarotenoid dioxygenase regulating abscisic acid biosynthesis in higher plants

“…22 Inhibitor 16 was obtained by reacting 2-thiopheneacetyl chloride and allylic alcohol 22 (protected as the neopentylglycol ketal). The xanthoxinlike allylic alcohol 22 was prepared through a Sonogashira coupling between the terminal acetylene in 21 23 and (Z)-3-iodobut-2-en-1-ol. Alcohol 22 was then converted to the phenyl sulfide 13 with 54%…”

Syntheses of C33-, C35-, and C39-Peridinin and Their Spectral Characteristics

“…We have already established a highly efficient method for the synthesis of peridinin, 8 which would be versatile and effective for providing various kinds of peridinin analogues, and have started an investigation to answer the question of why peridinin possesses an irregular C37 carbon skeleton along with allene and γ -ylidenbutenolide groups.…”

“…On the basis of the stereocontrolled synthesis of peridinin by the modified Julia coupling of 8 with 9 , 8 we synthesized C33, C35, and C39 peridinin (Figure 2). The synthesis of C33 peridinin 2 would be realized by the Pd-catalyzed one-pot ylidenbutenolide formation between the new iodide 5 and the reported alkyne 6 .…”

“…The synthesis of C33 peridinin 2 would be realized by the Pd-catalyzed one-pot ylidenbutenolide formation between the new iodide 5 and the reported alkyne 6 . 8 Meanwhile, the modified Julia coupling between C15-allenic segment 7 10,11 and C20-ylidenbutenolide segment 8 would produce C35 peridinin 3 . Furthermore, applying the same method to the coupling between C17-allenic segment 9 and C22-ylidenbutenolide segment 10 10 may produce the desired C39 peridinin 4 , if the coupling product would be enough stable to be handled.…”