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  • 28. Stereochemical Nomenclature; Racemization and Resolution Freshman Organic Chemistry (CHEM 125) Determination of the actual atomic arrangement in tartaric acid in 1949 motivated a change in stereochemical nomenclature from Fischer's 1891 genealogical convention (D, L) to the CIP scheme (R, S) based on conventional group priorities. Configurational isomers can be interconverted by racemization and epimerization. Pure enantiomers can be separated from racemic mixtures by resolution schemes based on selective crystallization of conglomerates or temporary formation of diastereomers. 00:00 - Chapter 1. Ambiguity in the D/L Genealogical Designations 10:15 - Chapter 2. The Discovery of Tartaric Acid's Atomic Arrangement and Notation by Priority 24:49 - Chapter 3. The Cahn-Ingold-Prelog Priority Scheme 34:12 - Chapter 4. Racemization and Epimerization Complete course materials are available at the Open Yale Courses website: This course was recorded in Fall 2008.
  • Aspects of Archaeology: Amino Acid Racemization Welcome to Aspects of Archaeology. In this series we take a closer look at different aspects of the world of archaeology. Today we examine Amino Acid Racemization.
  • Enols and tautomerism (1) Organic chemistry: Enols and enolates; tautomerism. Racemization at an α-carbon; deuterium exchange at an α-carbon. Enols as nucleophiles; acid-catalyzed α-halogenation. Boiling point of aldehydes and ketones This is a recording of a tutoring session, posted with the student's permission. These videos are offered on a "pay-what-you-like" basis. You can pay for the use of the videos at my website: www.freelance- For a list of all the available video series, arranged in suggested viewing order, go to my website. For a playlist containing all the videos in this series, click here: (1) Enols and enolates (2) Continued. Tautomerism (3) Continued (4) Continued (5) Continued (6) Continued. Racemization at an α-carbon (7) Continued. Deuterium exchange at an α-carbon (8) Continued. Enols as nucleophiles (9) Acid-catalyzed α-halogenation (10) Continued. Boiling point of aldehydes and ketones
  • In Focus: The Spitalfields Crypt Welcome to In Focus. In this series we take a closer look at particular sites, finds and objects from the world of Archaeology. Today we examine the Christ Church, Spitalfields, Crypt.
  • RS Nomenclature, RS Nomenclature Mechanism RS NOMENCLATURE -- RS NOMENCLATURE Arrangement of atoms or groups of a molecule in space is known as Configuration. We can decide through configuration that how the system will behave in optical situations. Here there is a use of two words R and S means R -- Rectus -- Right S -- Sinister -- Left R and S configuration shows right and left.
  • SN1 Racemization-Inversion
  • IU-Chemistry C341 Nucleophilic's Anonymous Organic chemistry: Essen One and Essen Two have a brief conversation about what they like best; substitution! (expand to view script) Script: SN1: Hey... you look nu. Is this your first time at nucleophilic's anonymous? SN2: Hey there. Yes, this is my first time. SN1: That's great. It's nice to meet you. My name is Essen One. What's yours? SN2: Essen? Well I'll be inverted! My name is Essen as well. Essen Two! It's great to meet you. SN1: Oh well I'll be racemized! SN1: What brings you here to nucleophilic's anonymous Essen? SN2: Well I believe I have a problem. I just love substitution so much. SN1: Ah, same here! All of us here love substitution. SN2: Well it's great to be among friends. I recently had a strong reaction with this primary girl. The site was just so (pause arms out to crowd) ... electrophilic. I had to attack it! What can I say... I'm a very strong nucleophile. SN1: I see... I find myself to be more neutral? I say the more the merrier. Two's a crowd but three's company... tertiary is the way to go! SN2: No way! Too much steric hindrance if you ask me. I just want to get in from the backside and make that leaving group leave! Quick, reactive, and easy my friend. SN1: No no no. It's all about the slow transition for me. I don't like to go straight for the substrate, ya know? After the leaving group leaves is when the fun starts! The carbocation is practically screaming for me to attack her. I simply cannot resist such a positive attraction. SN2: I see where ...