Asymmetric routes to pentadec-1-en-4-ol: application to the syntheses of aculeatins F and epi-F, (R)- and (S)-5-hexadecanolide and a formal synthesis of solenopsin

An Easy Route to Enantiomerically Enriched 7- and 8-Hydroxy­stearic Acids by Olefin-Metathesis-Based Approach

“…S)-(-)-1-Pentadecen-4-ol 6a: all spectroscopic data are in accordance with the literature 2,3. 98% ee, [α] D 25 = -5.2 (c = 1.03, CHCl 3 ), [lit 4.…”

“…Condensation of commercially available 4-pentenoic acid (5a, m = 2) and 5-hexenoic acid (5b, m = 3) with chiral nonracemic 1-pentadecen-4-ol (6a) 15,16 (n = 10) and 1-tetradecen-4-ol (6b) 17,18 (n = 9), respectively, was performed by using the Yamaguchi's esterification reaction 19 and afforded the dienic esters 4a and 4b in good chemical yields (Scheme 2). Yamaguchi's esterification resulted a clean and easy-to-perform reaction that gave higher yield than another method reported in the literature for esterification of long-chain homoallylic alcohols.…”

“…The moderate yields in the enzymatic resolution process might be due to the difficult extraction process after significant degradation of the supported enzyme. The unreacted esters (R)-(+)-7a and (R)-(+)-7b, both in 97% ee, were then hydrolyzed with two equivalents of K 2 CO 3 in MeOH at room temperature for 24 hours to furnish the corresponding alcohols (R)-(+)-6a 15,16,22,24 and (R)-(+)-6b,without affecting their enantiomeric composition.…”

The use of the lactone motif in chemical communication

“…53 It has been frequently synthesized as discussed elsewhere. 54 Enantioselective approaches with high ee were recently reported using either an enzymatic approach with alcohol dehydrogenase to form 6-hepten-5-olide, followed by metathesis and hydrogenation, 55 or by stereoselective formation of pentadec-en-4-ol via aldehyde aminooxylation and a RCM strategy. 54 Hydroxylated lactones are used by several insects.…”

Organocatalytic, Enantioselective Synthesis of Cyclohexadienone Containing Hindered Spirocyclic Ethers through an Oxidative Dearomatization/Oxa‐Michael Addition Sequence

“…Cyclohexadienone connected to a tetrahydrofuran moiety in a spiro‐fashion (CHD‐spiro‐THF) is a fascinating skeleton found in natural products aculeatins A–D and an aculeatin analogue A, which are active antimalarial agents against the P. falciparum 3D7 strain (Figure a) . There have been many attempts to synthesize such a CHD‐spiro‐THF moiety; most are achiral– or from chiral substrates –. To the best of our knowledge, a catalytic enantioselective synthesis of such a moiety is elusive.…”