Related Experiment Video
Updated: Oct 7, 2026

Enzymatic Synthesis of Epoxidized Metabolites of Docosahexaenoic, Eicosapentaenoic, and Arachidonic Acids
Published on: June 28, 2019
16alpha,17alpha-Epoxy-20-oxopregn-5-en-3beta-yl acetate
L C Andrade1, J A Paixão, M J de Almeida
1Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade de Coimbra, Portugal.
Abstract:
The title compound, C23H32O4, has a 3beta configuration, with the epoxy O atom at 16alpha,17alpha. Rings A and C have slightly distorted chair conformations. Because of the presence of the C5=C6 double bond, ring B assumes an 8beta,9alpha-half-chair conformation slightly distorted towards an 8beta-sofa. Ring D has a conformation close to a 14alpha-envelope. The acetoxy and acetyl substituents are twisted with respect to the average molecular plane of the steroid. The conformation of the molecule is compared with that given by a quantum chemistry calculation using the RHF-AM1 (RHF = Roothaan Hartree-Fock) Hamiltonian model. Cohesion of the crystal can be attributed to van der Waals interactions and weak intermolecular C-H.O interactions, which link the molecules head-to-tail along [101].
Related Concept Videos
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
Preparation of Epoxides
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of peroxy acids to...
Structure and Nomenclature of Epoxides
Alkylation of β-Diester Enolates: Malonic Ester Synthesis
α-Hydroxy Ketones via Reductive Coupling of Esters: Acyloin Condensation Overview
Esters to Carboxylic Acids: Acid-Catalyzed Hydrolysis
During hydrolysis, the ester is first activated towards nucleophilic attack through the protonation of the carboxyl oxygen atom by the acid catalyst. The protonation makes the ester carbonyl carbon more electrophilic. In the next step, water acts as a nucleophile and adds to the...

