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Colorado College Organic Chemistry Resource Repository

▶ Melting Point | MIT Digital Lab Techniques Manual – YouTube

via ▶ Melting Point | MIT Digital Lab Techniques Manual – YouTube.

Review Videos: Nucleophilic Additions to Carbonyls

NaBH4 Reduction:

The first 9 minute segment of this Khan Academy video provides a good review of NaBH4 reductions of aldehydes and ketones.  The last few minutes of the video are less useful and not recommended, due to the somewhat convoluted explanation of oxidation state assignment and an incorrectly drawn cyclohexanone structure.

LiAlH4 Reduction:

This Khan Academy video builds on the previous reduction video and includes a mechanism for the LAH reduction of esters.  This video also discusses selectivity of NaBH4 vs. LAH.

Grignard Reactions:

This Khan Academy video  provides a good overview of Grignard additions to produce secondary and tertiary alcohols. The first part of the video includes a detailed discussion of a postulated mechanism for formation of Grignard reagent via single electron transfers from Mg, which is much more detail than students in CH 250/251 need, so students should beware and try not to get hung up on this portion of the video.

Ketone Nomenclature:

This Khan Academy video gives useful introduction to ketone nomenclature (IUPAC and common naming systems).

 

Review Videos: Lewis Dot Structures

Review Video: Lewis Dot Structures with Single Bonds

Review Video: Lewis Dot Structures with Multiple Bonds

These Khan Academy videos provide a good review of Lewis dot structures.  Note that an “organic periodic table,” which is basically a compressed version of the periodic table in which the transition metal groups have been removed, is used in this lesson.  Students should watch this video with a “real” periodic table in hand to make sure they can follow the explanations.

Review Videos: Hybridization

sp3 hybridization video

sp2 hybridization video

sp hybridization video

More hybridization video

This set of Khan Academy videos explains the “construction” of sp3, sp2, and sp hybridized orbitals (on carbon) from atomic orbitals.  Each video is ~12 minutes long.  These videos should be helpful for students who would like some additional review of the concept of hybridization.  The sp video (3rd video in the sequence) also sums up the lessons by showing how to identify hybridization in a simple organic structure.

The final video in this set, “More hybridization,” discusses the use of “steric number” to determine hybridization and geometry (VSPER).

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