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Rules of the Day

3. For SN2 reactions using cyclohexane derivatives, the X must be in the axial position. If it is equatorial, the nucleophile cannot approach from the back of the C-X bond due to a "steric blockade" by the rest of the ring.

4. The point of Organic Chemistry is the synthesis of more complex molecules from simpler ones. Often, this requires multiple steps.

5. When doing synthesis problems (enhanced edition):

A) You must have your entire roadmap learned so you can recite the NIRRS parameters for each reagent, i.e. Nature of overall transformation ("locations" on the roadmap), the Intermediate or transition state (carbocation, anti-periplanar etc.), the Reagents and how to designate them, as well as any Regiochemistry (Markovnikov, etc.) and any appropriate Stereochemistry (syn, anti, InVERSiON, scrambled, etc).

B) Work backwards (learn to RECOGNIZE the appropriate reagents and starting materials by looking at the products) from the final product. DO NOT try to work forward from the starting materials. Please trust me on this.

C) Count carbons in the starting material(s) and product(s) to see if any carbon-carbon bonds need to be broken or made, thereby zeroing in on key steps. This will be far more important next semester, so you should get used to doing this now.

D) Pretty much all synthesis problems in OChem 1 involve traveling "north or south" on the so-called "I-35" reactions (alkanes SA, haloalkanes NB/SM, alkenes ATX, vicinal dihaloalkanes Waco, alkynes DFW) at least part way at some point during the synthesis. This is not a promise or a rule, just an observation.

7. The general rule of solvation is "like dissovles like", so polar, hydrogen bonding solvents dissolve polar, charged, or hydrogen bonding molecules and non-polar hydrocarbons dissolve nonpolar hydrocarbons. Non-polar material does not dissolve in polar solvents because the polar molecules stick to each other too well.