A highly diastereoselective method for the synthesis of cis-3-hexene-1,6-diols has been developed. This new reaction proceeds with excellent control of diastereoselectivity over four stereocenters and the double bond geometry. The diols are made in a one-pot procedure involving hydroboration of a terminal alkyne and transmetalation to zinc to give a divinylzinc intermediate. This intermediate undergoes reductive elimination, forming a C=C bond. In the absence of a trapping reagent, diene is liberated (70% yield); however, in the presence of ketones or aldehydes, the proposed intermediate metallocyclopentene is trapped via a double insertion of the carbonyl substrate. Workup provides the diols in 47-86% yield.
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http://dx.doi.org/10.1021/ja029449d | DOI Listing |
J Med Chem
January 2025
Ma̅tai Ha̅ora - Centre for Redox Biology and Medicine, Department of Biomedical Science and Pathology, University of Otago, Christchurch, Christchurch 8140, New Zealand.
In humans, the 2-oxoglutarate-dependent dioxygenases (2-OGDDs) catalyze hydroxylation reactions involved in cell metabolism, the biosynthesis of small molecules, DNA and RNA demethylation, the hypoxic response and the formation of collagen. The reaction is catalyzed by a highly oxidizing ferryl-oxo species produced when the active site non-heme iron engages molecular oxygen. Enzyme activity is specifically stimulated by l-ascorbic acid (ascorbate, vitamin C), an effect not well mimicked by other reducing agents.
View Article and Find Full Text PDFJ Med Internet Res
January 2025
School of Clinical Sciences, Monash University, Melbourne, Australia.
Background: eHealth interventions can favorably impact health outcomes and encourage health-promoting behaviors in children. More insight is needed from the perspective of children and their families regarding eHealth interventions, including features influencing program effectiveness.
Objective: This review aimed to explore families' experiences with family-focused web-based interventions for improving health.
Neurology
February 2025
Department of Medicine and Geriatrics, Tuen Mun Hospital, Hong Kong, People's Republic of China.
Background And Objectives: Mitochondrial disorders are multiorgan disorders resulting in significant morbidity and mortality. We aimed to characterize death-associated factors in an international cohort of deceased individuals with mitochondrial disorders.
Methods: This cross-sectional multicenter observational study used data provided by 26 mitochondrial disease centers from 8 countries from January 2022 to March 2023.
J Org Chem
January 2025
Key Laboratory of Chemistry and Engineering of Forest Products, State Ethnic Affairs Commission, Guangxi Key Laboratory of Chemistry and Engineering of Forest Products, Guangxi Collaborative Innovation Center for Chemistry and Engineering of Forest Products, Laboratory of Optic-electric Chemo/Biosensing and Molecular Recognition, Education Department of Guangxi Zhuang Autonomous Region, Guangxi Minzu University, Nanning 530006, China.
A regioselective [3 + 2] annulation of β,γ-alkynyl-α-ketimino esters with 1,3-dicarbonyls is disclosed. A series of -selective dihydrofurans bearing an exocyclic double bond and a quaternary carbon center are accessed without the usage of base. Control and deuterium-labeling experiments have been investigated to probe into the reaction mechanism.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
State Key Laboratory of Synthetic Biology, School of Chemical Engineering and Technology, Tianjin University, Yaguan Road 135, Jinnan District, Tianjin 300350, China.
Ursolic acid, a plant-derived pentacyclic triterpenoid with anti-inflammatory, antioxidant, and other bioactive properties, holds significant potential for use in nutritional supplements and drug development. However, its extraction from medicinal plants is inefficient due to low yield and dependence on seasonality and geography. Herein, we use modular metabolic engineering to enhance ursolic acid production in by dividing the biosynthetic pathway into five modules.
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