Construction of (Z,Z ) skipped 1,4-dienes. Application to the synthesis of polyunsaturated fatty acids and derivatives †

NickelButadiene Catalytic System for the Cross‐Coupling of Bromoalkanoic Acids with Alkyl Grignard Reagents: A Practical and Versatile Method for Preparing Fatty Acids

“…Fatty acids are essential to natural life because they act as key components in biological membranes and glycerides, as well as in various biologically active agents, such as prostaglandins and endocannabinoids 1. For the construction of structurally diverse carbon frameworks of fatty acids, transition‐metal‐catalyzed cross‐coupling reactions appear to be the most straightforward and efficient methods for carboncarbon bond formation and they have been employed in the synthesis of a wide variety of fatty acids with unsaturated bonds 2–4. However, these methods are limited to reactions at sp 2[3] or sp carbon atoms,4 in which the stereochemistry of the olefinic moieties that are being introduced must be controlled.…”

Short synthesis of labeled and unlabeled 6Z,9Z,12Z,15-hexadecatetraenoic acid as metabolic probes for biosynthetic studies on diatoms

“…Despite this importance as yet no synthesis of this unusual fatty acid was reported. This is at least partially due to the fact that the synthesis of homoconjugated tetraene systems, like it is found in C16:4 1 requires long sequences involving numerous coupling and protection steps (see Durand et al, 2000 for a review). Here we show that a one-pot bis-Wittig sequence, recently established in our lab for the production of homoconjugated dienes and trienes (Pohnert and Boland, 2000;Pohnert et al, 1999) can be extended for the generation of the homoconjugated tetraenoic acid C16:4 1 (Scheme 1).…”

Dialkynylation of aryl aldehydes using dialkynylboron chlorides: A transition-metal-free route to 1,4-diynes

“…In addition, 1,4-diynes are useful intermediates in the preparation of pyrroles [4e6] and furans [6] as well as skipped dienes [7,8]. In fact, a large number of polyunsaturated fatty acids have been synthesized from 1,4-diynes through a catalytic Lindar partial reduction reaction [9]. The generally used approach to 1,4-diynes [10] involves the cross-coupling of propargylic electrophiles with copper-acetylides [11,12].…”