CHEM 345 Study Guide - Final Guide: Diethyl Ether, Chlorophyll, Glycogen
Document Summary
Carbohydrates: usually contain c=o groups and oh groups. Exist primarily as hemiacetals and acetals: monosaccharides. D: oh on highest #ed c is on the right. L: oh on highest #ed c is on the left: disaccharides. Hydrolize to produce 2 mlc of monosaccharides. Ex: starch, cellulose: photosynthesis: 6co2 + 6hoh + solar energy/chlorophyll--> c6(hoh)6 + 6 o2, structural representations. Hemiacetals formed by an intramolecular reaction of the oh group at c5 w/ the aldehyde group. C1 is now a stereogenic center, forming 2 different diasteriomers (anomers) Mutarotation: evidence for and anomers; change in rotation toward an equilibrium value. Have different optical rotations, but when left to stand, rotation changes. Specific rotation of one form decreases and rotation of other form increases until both solutions show same value. Anomeric effect believed to be caused by hyperconjugation: glycoside formation. Glycoside + hoh/h3o--->glucose + aglycone (alcohol: enolization. Dissolving monosaccharides in aqueous base causes them to undergo enolization and tautomerizations that lead to isomerization.
