One-step conversion of protected lactols into lactones

Synthesis of the originally proposed structures of elatenyne and an enyne from Laurencia majuscula

“…16 We therefore aimed to synthesise the bis-d-lactone 8 by oxidation of the corresponding bis-methyl acetal 9. 17 The bis-acetal 9 would be prepared from the corresponding dialdehyde 10 under equilibrating conditions with acid catalysis. Ultimately the dialdehyde would be synthesised from the commercially available tartrate-derived acetonide 12.…”

Asymmetric Synthesis of the β-Methyl-Substituted Analogues of (+)-Tanikolide and (–)-Malyngolide

“…Previously, the application of this method, reported by Grieco and co-workers, on protected δ-lactols, i.e. 20/21 gave low yields of the corresponding δ-lactones [53]. A subsequent report by Masaki and co-workers found the addition of Et 3 N was necessary after initial oxidation to convert the unstable hemiacetal m-chloroperbenzoate (24ii) to the δ-lactone [54] (Scheme 2.5).…”

The Enantioselective Formal Synthesis of (+)-Avenaciolide and (+)-Isoavenaciolide from Tri-O-acetyl-D-glucal Using a Ring Contraction Reaction as the Key Step

“…The oxidation of lactone 11a with the Jones reagent led to the bis-lactone compound (ϩ)-4 in a 48% yield. This yield was improved by using MCPBA and BF 3 ⋅Et 2 O (Grieco oxidation [14] ), and the desired bis-lactone (ϩ)-4 was obtained in a 76% yield (Scheme 2), thus completing the formal synthesis of (ϩ)-Avenaciolide. Nevertheless, when lactone 11b was oxidized with MCPBA the bis-lactone objective (ϩ)-5 was not obtained.…”