A Divergent Enantioselective Synthesis of 9‐J₁‐Phytoprostane and 9‐A₁‐Phytoprostane Methyl Ester

Abstract

The first syntheses of 9‐J1‐phytoprostane and 9‐A1‐phytoprostane methyl ester were achieved enantioselectively using a divergent approach from a common intermediate sulfone 4. The divergence was accomplished using a sigmatropic rearrangement (swap protocol) to give sulfone 5 in 47 % overall yield. The two upper side‐chains, with a stereodefined E double bond, were installed using consolidated Julia–Lythgoe olefination reactions of sulfones 4 and 5, with the same enantiopure α‐protected aldehyde 6.

Total syntheses of all tri-oxygenated 16-phytoprostane classes via a common precursor constructed by oxidative cyclization and alkyl–alkyl coupling reactions as the key steps

“…40 An individual total synthesis of 16-E 1 -PhytoP was also published, based on the Friedel-Crafts acylation of furan, followed by a Piancatelli rearrangement and attachment of the ω-chain by 1,4-conjugate addition after enzymatic resolution. 41 The total syntheses of ring-isomeric cyclopentenone PhytoP, namely 9-and 16-B 1 -and L 1 -PhytoP as well as 9-A 1 -and 9-J 1 -PhytoP, were accomplished by the Vidari-Zanoni group, 42,43 whereas Riera's group developed an individual approach to 16-B 1 -and 9-L 1 -PhytoPs. 44 A total synthesis of 16-D 1t -PhytoP was never accomplished.…”

Nonenzymatic α-Linolenic Acid Derivatives from the Sea: Macroalgae as Novel Sources of Phytoprostanes

“…Two regioisomeric series (16-G 1 -phytoprostanes and 9-G 1 -phytoprostanes) can be generated depending on the position where the hydrogen abstraction occurs and the oxygen atoms are inserted in the PUFA backbone . G 1 -phytoprostanes are then precursors of different classes of cyclic phytoprostanes, named in analogy with the prostaglandin nomenclature system as A 1 , B 1 , D 1 , E 1 , F 1 , dJ 1 , and L 1 -phytoprostanes, with the latter being the regioisomer of B 1 -phytoprostane. , This large family of regio- and stereoisomeric prostaglandin-like compounds has been found to occur constitutively in plants; however, reactive oxygen species (ROS) generated under the influence of both biotic and abiotic factors interfere with cellular redox balance and lead to enhanced formation of phytoprostanes, inducing, for instance, the biosynthesis of secondary metabolites, the expression of genes involved in detoxification processes, and the regulation of the oxidative stress-related mitogen-activated protein kinase (MAPK)-dependent signaling pathway. ,− Therefore, these oxylipins can function not only as defense signals, but also as endogenous mediators capable of preventing cellular damage …”