Synthesis of the proposed structure of queenslandon

Chemoenzymatic asymmetric total synthesis of naturally occurring resorcylic acid lactones hamigeromycins F and G

“…Conversely, the absence of any substituent at the C 5 -position led to a successful RCM reaction of the similar substrate as documented earlier for the total synthesis of structurally related queenslandon RALs. 18…”

“…Organic & Biomolecular Chemistry ted earlier for the total synthesis of structurally related queenslandon RALs. 18 As attempted late-stage RCM and CM reactions failed to construct the crucial C 1′ -C 2′ bond, we thought to adopt a strategy involving late-stage intramolecular macrolactonization using Brabender's protocol, to offer a more flexible and direct approach for constructing the 14-membered macrolactone core present in RALs. Julia-Kocienski olefination 19 was proposed for achieving C 1′ -C 2′ olefinic unsaturation.…”

Synthesis of Luffarin L and 16-epi-Luffarin L Using a Temporary Silicon-Tethered Ring-Closing Metathesis Reaction

“…This compound was deprotected with PPTS to give triol 13 that by treatment with benzaldehyde dimethyl acetal in the presence of camphorsulfonic acid gave 14 . Oxidation of 14 with Dess–Martin periodinane − led to ketone 15 that without isolation was transformed by Wittig reaction into compound 16 Z . The olefination reaction was optimized under diverse conditions using several reactants, bases, and temperatures to obtain the desired regioisomer 16 Z .…”

Update 1 of: Macrolactonizations in the Total Synthesis of Natural Products

“…This reaction has been used in a number of 11- to 16-membered macrolactones, ,,− in the total syntheses of natural products such as (+)-amphidinolide K (eq a in Scheme ), 19- epi -avermectin B 1 , (+)-brefeldin C, citreofuran, antibiotics derived from erythromycin, , (+)-gloeosporone, − hypothemycin, cyclothialidine, lasiodiplodin, lobotamide C, ,, latrunculins A and B, − laulimalide, ,, where Yamaguchi and Keck methodologies result in Z / E isomerization of the conjugated double bond (eq b in Scheme ), leucascandrolide A, − (+)-milbemycin β 3 , , (+)-patulolide, suspensolide, , diolides UK-2A and UK-3A, , verrucarin A, zearalane, and aplyronine A analogues, a formal synthesis of apicularen A, queenslandon, , retipolide E and ornatipolide, tedanolide, , and xestodecalactone A …”