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Solutions to Problems 467 58. You can find a good conformational picture of on page 1146 of the textbook. as the left- hand part of the structure of lactose. Switch stereochemistry at C1 for the α isomer. Notice in the answer below how the name, translates into the structure: OH CH₂OH 0 OH HO 0 HO 0 B OH 3 HO 59. The hydroxyl group at C1 leaves most readily when protonated. because a resonance-stabilized carbocation is produced. CH₂OH CH₂OH CH₂OH HO HO :NH3 HO 0 + HO OH₂ -H₂O HO + Then HO NH₂ OH OH OH 60. (a) Aldol condensations! Abbreviated mechanisms are shown below. Refer to Section 18-6 for more details. if necessary. H CH₂OH CH₂OH C 0 HO: c=0 + H OH D-sorbose and D-fructose mainly CHOH CH₂OH H CH₂OH CH₂OH CH₂OH HO: c=0 dendroketose CH₂OH CH₂OH (b) The hint is supposed to make you think about enolate ions. Glyceraldehyde and are readily interconverted in aqueous basic solution via enolates and enols. CH₂OH CHOH CHOH H-OH CH₂OH CH₂OH CH₂OH CH₂OH Enolate Enol HC HC=0 II CHO C-OH OH CHOH CH₂OH CH₂OH CH₂OH Enolate