Related Experiment Video
Updated: Mar 13, 2026

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts
Published on: February 24, 2015
Total synthesis and stereochemical determination of yoshinone A
Seiichi Shinomiya1, Arihiro Iwasaki1, Osamu Ohno2
1Department of Chemistry, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan.
Abstract:
In 2014, the γ-pyrone-containing polyketide, yoshinone A, was isolated from the marine cyanobacterium Leptolyngbya sp. and its structure was determined. Yoshinone A inhibited differentiation of 3T3-L1 cells into adipocytes, with an EC50 value of 420 nM without any cytotoxicity, and therefore is expected to be a lead compound for obesity drugs. To establish its absolute configuration, and to provide sufficient amounts for further research, the total synthesis of yoshinone A was achieved through synthesis of its two possible diastereomers.
More Related Videos
11:09Constructing Thioether/Vinyl Sulfide-tethered Helical Peptides Via Photo-induced Thiol-ene/yne Hydrothiolation
Published on: August 1, 2018
09:54Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes
Published on: September 12, 2018
Related Concept Videos
Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
SN1 Reaction: Stereochemistry
In the first step of an SN1 reaction, the bond between the electrophilic carbon and the leaving group ionizes to generate the carbocation intermediate. The second step of the mechanism is the nucleophilic attack.
In the formed carbocation, the positively charged carbon is sp2 hybridized with a trigonal planar geometry. As all the three substituents lie on the same plane, a plane of symmetry for the...
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
SN2 Reaction: Stereochemistry
If the substrate is an achiral molecule at the α-carbon, the inversion of configuration is not...
Stereoisomerism of Cyclic Compounds
E2 Reaction: Stereochemistry and Regiochemistry
When a substrate with two different β hydrogens undergoes an E2 elimination, the presence of a strong base can yield two regioisomeric alkenes. The more-substituted alkene is the major...