Related Experiment Video
Updated: Aug 17, 2026

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy
Published on: November 9, 2019
Versatile and stereoselective syntheses of orthogonally protected beta-methylcysteine and beta-methyllanthionine
Radha S Narayan1, Michael S Vannieuwenhze
1Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, MC 0358, La Jolla, California 92093, USA.
Abstract:
[reaction: see text] Lantibiotics are a class of lanthionine (and/or beta-methyllanthionine)-containing peptides with antibioitic activity against Gram-positive bacteria. As part of our research effort directed toward the synthesis and mechanistic study of the lantibiotic peptide mersacidin (1), we report stereoselective syntheses of orthogonally protected beta-methylcysteine (beta-MeCys) and beta-methyllanthionine (beta-MeLan), two key nonnatural amino acid components of the mersacidin architecture.
Related Concept Videos
Preparation and Reactions of Sulfides
Alkylation of β-Diester Enolates: Malonic Ester Synthesis
Synthesis of α-Substituted Carbonyl Compounds: The Stork Enamine Reaction
Alkylation of β-Ketoester Enolates: Acetoacetic Ester Synthesis
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.
α-Alkylation of Ketones via Enolate Ions

