a) Fill in the table below (show calculations and workings) b) Write the reaction formula for this experiment c) Give a
Posted: Mon May 23, 2022 12:07 am
a) Fill in the table below (show calculations and workings)
b) Write the reaction formula for this experiment
c) Give a full detailed mechanism (including curly arrows, by products, etc) for this experiment
1. Peracetylation of D-Lactose (a disaccharide) 1,2,2,3,3'4',6,6'-Octa-O-acetyl-B-D-lactose (1) OH OH OH OH HO- HO- C12H22011 342.2965 OH NaOAc Ac₂0 OH ACO AcO- OAC Compound MW (g/mol) eq n (mmol) m (g) V (ml) d (g/ml) D-Lactose 342.30 1 29.21 10 Sodium acetate 82.03 48.76 4 1.6 25 Acetic anhydride 102.09 741.90 70 1.082 Apparatus: 250 ml round bottom flask, condensor, open to air, magnetic stirrer, oil bath Reaction temperature: 140 °C Reaction time: TLC: EtOAc/Tol 2:1 Reaction molarity: 0.4 Anhydrous sodium acetate is suspended in acetic anhydride and heated to 140 °C. About 2 g of the sugar is added to the mixture, stirring shortly at 140 °C, then removal from heat. The remaining sugar is added in portions, always ensuring that the reaction temperature is maintained. After complete addition of the sugar, stirring until boiling subsides, heat up again to 140 °C for 10 min. Reaction is allowed to cool and is poured onto 250 ml of cracked ice, let stand for 1-2 h. The precipitated crystalline material is filtered and washed with ice-cold water. Recrystallization from EtOH. OAC OACACO- OAC C28H38019 678.5899 OAC
b) Write the reaction formula for this experiment
c) Give a full detailed mechanism (including curly arrows, by products, etc) for this experiment
1. Peracetylation of D-Lactose (a disaccharide) 1,2,2,3,3'4',6,6'-Octa-O-acetyl-B-D-lactose (1) OH OH OH OH HO- HO- C12H22011 342.2965 OH NaOAc Ac₂0 OH ACO AcO- OAC Compound MW (g/mol) eq n (mmol) m (g) V (ml) d (g/ml) D-Lactose 342.30 1 29.21 10 Sodium acetate 82.03 48.76 4 1.6 25 Acetic anhydride 102.09 741.90 70 1.082 Apparatus: 250 ml round bottom flask, condensor, open to air, magnetic stirrer, oil bath Reaction temperature: 140 °C Reaction time: TLC: EtOAc/Tol 2:1 Reaction molarity: 0.4 Anhydrous sodium acetate is suspended in acetic anhydride and heated to 140 °C. About 2 g of the sugar is added to the mixture, stirring shortly at 140 °C, then removal from heat. The remaining sugar is added in portions, always ensuring that the reaction temperature is maintained. After complete addition of the sugar, stirring until boiling subsides, heat up again to 140 °C for 10 min. Reaction is allowed to cool and is poured onto 250 ml of cracked ice, let stand for 1-2 h. The precipitated crystalline material is filtered and washed with ice-cold water. Recrystallization from EtOH. OAC OACACO- OAC C28H38019 678.5899 OAC