I. Introduction to Anti-Aromatic SystemsII. If molecules can exist as aromatic molecules, they willI. Analyzing Ketone StructureII. Consequences of the Structures of Ketones and AldehydesIII. Hydrate EquilibriumIV. Hydrate Formation in Basic vs. Acidic ConditionsI. Analyzing Ketone Structurea. In this chapter, we will be protonating carbonyls using lone pairsII. Consequences of the Structures of Ketones and Aldehydesa. The carbonyl oxygen is the basic site: the site of protonationb. The carbonyl carbon is the electrophilic sitec. The alpha Hydrogen are VERY ACIDICi. Pka = 20ii. The alpha C is attached to the carbonyl C, and so the H on the alpha C are called alpha H. These Hydrogens will undergo reactions that will be discussed later.III. Hydrate Equilibriuma. A ketone + water  geminol diol (or the hydrate of a ketone/aldehyde)i. Each Carbon is bonded to two hydroxyl groups. The word, “geminol,” means that the hydroxyl groups are bonded on the SAME CARBONii. Not vicinal! Vicinal would mean that the hydroxyl groups are bonded to adjacent CarbonsIV. Hydrate Formation in Basic vs. Acidic Conditionsa. In Basic conditions (in equilibrium! You must know mechanisms for both the forward and reverse reactions)i. Forward reaction:1. Overall: ketone + NaOH  geminol diola. – OH in solution, attacks electrophilic carbonyl C, break pi bond, electrons move to oxygen making the O negatively charged.i. – OH is a great nucleophile (full blown negative charge). If it were water, it would not be nucleophilic enough. This is important when choosing which player attacks the electrophilic carbonyl C.ii. The ion formed from this step is called: tetrahedral alkoxide intermediateb. Lone pair on negatively charged O attack water (protonation of the oxygen, deprotonation of the water)i. You have regenerated your catalyst (– OH) and formed your geminol diol.c. This is the same forward reaction in forming the hemiacetal.ii. The reverse of hydrate formation in basic conditions:1. Overall: Geminol diol + – OH (exists as NaOH) ketone + – OHa. Hydroxide deprotonates the H of the hydroxyl group of the geminol diol.i. This destabilizes the original geminol diol greatlyb. Lone pair on destabilized oxygen form pi bond, kicking out the other hydroxyl group. You have formed your ketone, and hydroxide as the productb. Acidic hydrate equilibrium:i. Overall forward: generic ketone + H2SO4, cat, water  geminol diol1. Protonate the carbonyl O. Form positively charged O. Note that there is a net dipole towards the O, and the carbonyl C has a partial positive charge.2. O from water attacks that partially positively charged C. Breaking the pi bond, kicking the electrons out onto O.3. Almost there! Now you have water attached to the once carbonyl C, and a hydroxyl group attached to that same C. To make the geminol diol, you need to deprotonate. BUT you are in ACIDIC solution. So the only option is water.a. Water deprotonates the water, and you have formed your geminol diol AND regenerated your catalyst. That’s how you know you did it right!ii. The reverse hydrate formation in acidic conditions:1. Propose a mechanism for the reverse reaction, as requested by the professor.CHEM 0320 1nd Edition Lecture 15Outline of Last Lecture I. Introduction to Anti-Aromatic Systems II. If molecules can exist as aromatic molecules, they willOutline of Current Lecture I. Analyzing Ketone Structure II. Consequences of the Structures of Ketones and Aldehydes III. Hydrate Equilibrium IV. Hydrate Formation in Basic vs. Acidic Conditions Current Lecture I. Analyzing Ketone Structure a. In this chapter, we will be protonating carbonyls using lone pairsII. Consequences of the Structures of Ketones and Aldehydes a. The carbonyl oxygen is the basic site: the site of protonation b. The carbonyl carbon is the electrophilic site c. The alpha Hydrogen are VERY ACIDICi. Pka = 20 ii. The alpha C is attached to the carbonyl C, and so the H on the alpha C are called alpha H. These Hydrogens will undergo reactions that will be discussed later.III. Hydrate Equilibrium a. A ketone + water  geminol diol (or the hydrate of a ketone/aldehyde) i. Each Carbon is bonded to two hydroxyl groups. The word, “geminol,” means that the hydroxyl groups are bonded on the SAME CARBONii. Not vicinal! Vicinal would mean that the hydroxyl groups are bonded to adjacent CarbonsIV. Hydrate Formation in Basic vs. Acidic Conditions These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.a. In Basic conditions (in equilibrium! You must know mechanisms for both the forward and reverse reactions)i. Forward reaction:1. Overall: ketone + NaOH  geminol diol a.– OH in solution, attacks electrophilic carbonyl C, break pi bond, electrons move to oxygen making the O negatively charged. i.– OH is a great nucleophile (full blown negative charge). If it were water, it would not be nucleophilic enough. This is important when choosing which player attacks the electrophilic carbonyl C.ii. The ion formed from this step is called: tetrahedral alkoxide intermediate b. Lone pair on negatively charged O attack water (protonation of the oxygen, deprotonation of the water) i. You have regenerated your catalyst (– OH) and formed your geminol diol.c. This is the same forward reaction in forming the hemiacetal. ii. The reverse of hydrate formation in basic conditions:1. Overall: Geminol diol + – OH (exists as NaOH) ketone + – OHa. Hydroxide deprotonates the H of the hydroxyl group of thegeminol diol.i. This destabilizes the original geminol diol greatlyb. Lone pair on destabilized oxygen form pi bond, kicking out the other hydroxyl group. You have formed your ketone, and hydroxide as the productb. Acidic hydrate equilibrium: i. Overall forward: generic ketone + H2SO4, cat, water  geminol diol 1. Protonate the carbonyl O. Form positively charged O. Note that there is a net dipole towards the O, and the carbonyl C has a partial positive charge. 2. O from water attacks that partially positively charged C. Breaking the pi bond, kicking the electrons out onto O. 3. Almost there! Now you have water attached to the once carbonyl C, and a hydroxyl group attached to that same C. To make the geminol diol, you need to deprotonate. BUT you are in ACIDIC solution. So the only option is water. a. Water deprotonates the water, and you have formed your geminol diol