Related Experiment Video
Updated: Jul 8, 2026

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Total synthesis of (-)-bitungolide F and determination of its absolute stereochemistry
Subhash Ghosh1, Soma Uday Kumar, J Shashidhar
1Indian Institute of Chemical Technology, Hyderabad 500 007, India. subhash@iict.res.in
Abstract:
A highly convergent total synthesis of bitungolide F leading to the assignment of its absolute stereochemistry is described. The key steps include a Horner-Wadsworth-Emmons olefination to construct the C7-C8 bond, a Wittig reaction to introduce the conjugate E,E-olefinic moiety in the molecule, and finally a ring-closing metathesis reaction to construct the six-membered alpha,beta-unsaturated delta-lactone of the molecule. Modified Evans's syn-aldol reaction, using Crimmins's protocol, was used to install the stereochemistries at the C4 and C5 centers. The stereochemistry at C9 was introduced by means of hydroxy-directed reduction of the C9 keto using Evans's protocol.
Related Concept Videos
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
Prochirality
Fischer Projections
Stereoisomerism of Cyclic Compounds

