Related Experiment Video
Updated: Jun 24, 2026

A Direct, Early Stage Guanidinylation Protocol for the Synthesis of Complex Aminoguanidine-containing Natural Products
Published on: September 9, 2016
Bioactive montanine derivatives from halide-induced rearrangements of haemanthamine-type alkaloids. Absolute
Juan C Cedrón1, Ana Estévez-Braun, Angel G Ravelo
1Instituto Universitario de Bio-Organica "Antonio Gonzalez", Universidad de La Laguna, Av. Astrofísico Francisco Sanchez 2, 38206 La Laguna-Tenerife, Spain.
Abstract:
An unexpected rearrangement of haemanthamine-type alkaloids in the presence of halogenating agents has been found. Rearranged compounds present the 5,11-methanomorphantridine framework characteristic of montanine-type alkaloids. These compounds are difficult to obtain because of their scarcity in natural sources and because the synthetic approaches developed so far require numerous steps. Vibrational circular dichroism (VCD) spectroscopy was used to determine the absolute configuration of one of the rearranged compounds. Several rearranged alkaloids showed antimalarial activity.
More Related Videos
11:04Preparation of Enantiopure Non-Activated Aziridines and Synthesis of Biemamide B, D, and epiallo-Isomuscarine
Published on: June 13, 2022
10:42Preparation of N-(2-alkoxyvinyl)sulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines
Published on: January 3, 2018
Related Concept Videos
Preparation of 1° Amines: Hofmann and Curtius Rearrangement Overview
Halogenation of Alkenes
Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
Radical Halogenation: Stereochemistry
Halogenation to form a new chiral center:
Adrenergic Agonists: Chemistry and Structure-Activity Relationship
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of the aromatic...
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
Nucleophilic Aromatic Substitution: Elimination–Addition