Rules of the Day 2-26-07

Mechanism Sheet for Today's Lecture

1. Carboxylic acids react with SOCl2 to give acid chlorides via a chlorosulfite intermediate that then reacts according to Mechanism B to give the acid chloride. This is a very valuable reaction because acid chlorides can be easily converted into other carboxylic acid derivatives.

2. The haloform reaction converts methyl ketones to carboxylates. The mechanism is the interesting part, involving enolate formation in base, three sequential replacements of H with Br, then then attack of OH- on the carbonly, loss of -CBr3 (Mechanism B).

3. b-Keto acids and b-dicarboxylic acids can be decarboxylated via a six-membered ring transition state facilitated by a hydrogen bond and six-membered ring conformation that means they are "poised" to react.

Homework: Contiinue Working on Homework Problem Set 5. It will be due before class next Wednesday, February 28. Reading: Sections 18.1-18.4, Problems in Book: 18.1-18.5, 18.12, 18.13 You will not turn these in but they are very helpful to PREPARE for the next lecture.