2111-53-7Relevant articles and documents
29. Total synthesis of crenulatan diterpenes: Strategy and stereocontrolled construction of a bicyclic keto-lactone building block
He,Pinard,Paquette
, p. 391 - 402 (1995)
The bicyclic keto lactone 26 was synthesized for the purpose of developing a viable route to marine diterpenes of the crenulatan type. Following the efficient conversion of (S)-citronellol (5) to the allylated alcohol 9a, the α,β -unsaturated lactone 12 was efficiently accessed in preparation for stereocontrolled conjugate addition. The hydroxymethyl equivalent most suited to this task was (i-PrO)Me2SiCH2MgCl, which gave 13 predominantly in the presence of CuI and Me3SiCl. Once the OH group was deprotected (→14), it proved an easy matter to implement acid-catalyzed isomerization to lactone 15, oxidation of which gave the pivotal aldehyde 16. Condensation of 16 with PhSeCH2Li led via 21 to 22. Once the OH group was protected (→22b), it proved possible to effect aldolization with crotonaldehyde (→23). Exposure of 23 to acid gave the sub-target compound 25. Its subsequent oxidation and thermal activation resulted in sequential selenoxide elimination with Claisen rearrangement (→26). The structural features of 26 require that a chair-like transition state be adopted during the [3.3]sigmatropic event. With the clarification of these issues, a highly serviceable and more advanced assault on the crenulatans should prove capable of being mounted.
Oxidation of Primary Alcohols and Aldehydes to Carboxylic Acids via Hydrogen Atom Transfer
Tan, Wen-Yun,Lu, Yi,Zhao, Jing-Feng,Chen, Wen,Zhang, Hongbin
supporting information, p. 6648 - 6653 (2021/09/08)
The oxidation of primary alcohols and aldehydes to the corresponding carboxylic acids is a fundamental reaction in organic synthesis. In this paper, we report a new chemoselective process for the oxidation of primary alcohols and aldehydes. This metal-free reaction features a new oxidant, an easy to handle procedure, high isolated yields, and good to excellent functional group tolerance even in the presence of vulnerable secondary alcohols and tert-butanesulfinamides.
Amides as bioisosteres of triazole-based geranylgeranyl diphosphate synthase inhibitors
Goetz, Daniel B.,Holstein, Sarah A.,Varney, Michelle L.,Wiemer, David F.
, (2020/07/10)
Geranylgeranyl diphosphate synthase (GGDPS) inhibitors are of potential therapeutic interest as a consequence of their activity against the bone marrow cancer multiple myeloma. A series of bisphosphonates linked to an isoprenoid tail through an amide linkage has been prepared and tested for the ability to inhibit GGDPS in enzyme and cell-based assays. The amides were designed as analogues to triazole-based GGDPS inhibitors. Several of the new compounds show GGDPS inhibitory activity in both enzyme and cell assays, with potency dependent on chain length and olefin stereochemistry.
A general approach to iridoids by applying a new Julia olefination and a tandem anion-radical-carbocation crossover reaction
?ehová, Lucie,Dra?ínsky, Martin,Jahn, Ullrich
supporting information, p. 9612 - 9621 (2016/10/22)
A unified, asymmetric approach to the total synthesis of naturally occurring iridoids is presented. The synthesis features a recently discovered ortho → α transmetalation of alkyl aryl sulfone carbanions, thus enabling Julia reactions, by which so far har
