EXamples: aliphatics O 10% NaOH OH O h H 5℃ H CH Naoh CH3CH2 CHO +(CH3) CHCHO 25°C CH3CH2CH-C-CHO OH CH3 Naoh CH3CH2 CHO +(CH3) CHCHO 80°C (CH3)2 CHCH=C-CHO CH3 NaOH H3C、 H3C CHCH2 CHO+CH2 COCH3@C H3C CHCH2 CH=CHCOCH 60%
60% Examples：aliphatics + 30℃ 80℃ 25℃ NaOH CH3CH2CHO (CH3) 2CHCHO CH3CH2CH C CHO CH3 OH CH3 CH3CH2CHO + (CH3) 2CHCHO NaOH (CH3) 2CHCH C CHO CH3 CHCH2CHO H3C H3C + CH3COCH3 NaOH CHCH2CH H3C H3C CHCOCH3 H O + H O H 10% NaOH 5 ℃ H OH O
活性比较:酮<醛 Ba(OH2 CH3-C H2C-C-CH3 CH3 CHa 2或H3PO H3C-C-CH2-C-CH OH CH3 O H3C-C=CH-C-CH3 71% CHO H2o OHC-(CH2)3-CH-CHO 115°C C3H7 C3H7 62
活性比较：酮 < 醛 CHO C3H7 115℃ H2O OHC (CH2) 3 CH CHO C3H7 CH C CH3 O H3C C CH3 I 2或H3 PO4 CH2 C CH3 O H3C C CH3 OH Ba(OH) 2 H2C C CH3 O H CH3 C + CH3 O 71% 62%
Review 2012. 4.24 Condensation reaction is a chemical reaction in which two molecules or moieties (functional groups)combine to form one single molecule, together with the loss of a small molecule or not losing anything, such as d-a When two separate molecules react, the condensation is termed intermolecular If the union is between atoms or groups of the same molecule, the reaction is termed intramolecular condensation, and in many cases leads to ring formation
Review 2012,4,24 • Condensation reaction is a chemical reaction in which two molecules or moieties (functional groups) combine to form one single molecule, together with the loss of a small molecule or not losing anything, such as D-A. • When two separate molecules react, the condensation is termed intermolecular. • If the union is between atoms or groups of the same molecule, the reaction is termed intramolecular condensation, and in many cases leads to ring formation
Functionalized alkylation a-hydroxyalkylation Aldol condensation, Prins, Benzoin etc a-chloroallkylation Blanc reaction, a-aminoalky lation Mannich, Pictet-Spengler, Strecker, etc
Functionalized alkylation • -hydroxyalkylation – Aldol condensation, Prins, Benzoin, etc. • -chloroalkylation – Blanc reaction, • -aminoalkylation – Mannich, Pictet-Spengler, Strecker,etc
Review 2012. 4.24 Example of intramolecular condensation 1)Dieckmann condensation: two ester groups of a single diester molecule react with each other to lose a small alcohol molecule and form a B-ketoester product OR Base OR O -ROH OR 2 Robinson Annulations
Review 2012,4,24 • Example of intramolecular condensation • 1) Dieckmann condensation: two ester groups of a single diester molecule react with each other to lose a small alcohol molecule and form a β-ketoester product. • 2) Robinson Annulations