Note: Acid chlorides are one of the only carboxylic acid derivatives reactive enough to produce anhydrides by nucleophilic acylation

Note: Ester preparation from a reactive acid chloride, in this case with a base driven nucleophile

Note: Ester preparation from a reactive anhydride. Note the leftover 'leaving group' from the anhydride.

Warning: Base driven ester preparation will not work against carboxylic acids because acid-base reactions will occur first.

Warning: No Reaction - Primary Alkyl Halide, Weak Nucleophile
Weak nucleophile excludes Sn2, E2.
Primary alkyl halide would yield unstable carbocation, so no Sn1 or E1 allowed either

Note: Sn1, E1 Competition - Secondary Alkyl Halide, Weak Nucleophile

Note: Racemization (loss of stereospecificity) by Sn1 (compare to Sn2).

Note: Zaitsev rule preference for more highly substituted alkene, and preference for largest substituents oriented trans to one another

Note: Sn1, E1 Competition - Tertiary Alkyl Halide, Weak Nucleophile

Note: Racemization (loss of stereospecificity) by Sn1 (compare to Sn2).

Note: Zaitsev rule preference for more highly substituted alkene

Note: E1 results in racemization, no stereospecificity. Always prefer the larger groups trans to each other

Note: Sn1 competition. Note that a carbocation rearrangement (hydride shift) occured

Note: E1 results in racemization, no stereospecificity. Always prefer the larger groups trans to each other

Note: Sn1 competition. Note that a carbocation rearrangement (hydride shift) occured

Note: Sn1 at primary benzylic halide. Apparent primary carbocation seems disfavored, but resonance at the benzylic position stabilizes it