|
Reaction #7: Addition of carbene (:CR2) to form a cyclopropane (Could not find a suitable video for cyclopropane synthesis)  Reaction #8: Halogenation-- addition of Br2, Cl2, with or without a protic solvent -Forms two adjacent anti-halogens in aprotic solvent. -Forms two adjacent anti- halogen + solvent in protic solvent (ROH or H2O) Note: the opening of the halonium ion (halogen ring) can occur not just with H2O, but with other alcohols (ROH) Reaction 9: Epoxidation by peroxycarboxylic acid -Forms an epoxide This reaction forms an epoxide. This is a good time to review epoxide ring opening from 118A: https://ericpdotutoring.weebly.com/week-six Note for synthesis: Opening epoxides with NaOH or H+, H2O will form two alcohols anti to one another. This is in contrast to the next reaction, reaction 10- KMnO4 or OsO4, which forms syn diols (2 alcohols). Reaction 10: Dihydroxylation by KMnO4 or OsO4 -Forms two adjacent, syn- alcohols  Note: Nasiri teaches different reagents than what is shown in the video. Conceptually and mechanistically, the video is still helpful. Also: we did not cover the last reaction shown: cleavage of alkenes (beginning 9:45~ onwards) Instead: We learned Ozonolysis for cleavage of alkenes *Feel free to use reactions that Nasiri did not teach on synthesis questions on exams* Reaction 11: Ozonolysis -Cleaves alkenes and replaces them with carbonyls  Note: Khan Academy uses DMS as their second step. DMS = dimethyl Sulfide = CH3SCH3 Note: The first step of Ozonolysis's mechanism is very similar to reaction 10 with KMnO4/ OsO4
0 Comments
Leave a Reply. |
