McMurry, pp 195 - 198:
Problems 6.18, 19, 22-26, 28-32, 34, 35, 38, 39, 43-48, 51, 55
1. Write complete names for each of the following compounds, including designation
of stereochemistry:
1a) (3S,6R)-3-bromo-2,3,6,7,7-pentamethylnonane
1b) (2S,3S)-1,1-dichloro-2,3-dimethylcyclopropane
1c) (3R,4R)-4-chloro-3-fluoro-1,1-dimethylcyclohexane
2. All of the naturally occuring amino acids are called L because
they have a stereochemistry that was historically correlated with one stereoisomer
of glyceraldehyde, shown below.
L-Glyceraldehyde and the natural amino acids all have the S absolute configuration.
The two exceptions are glycine and cysteine. Look up their 3-dimensional
structures and explain why they are different.
Glycine does not have a stereocenter (R = H).
Cysteine has a sulfur substituent (R = CH2SH), but it does have the same
relative configuration as all the other L-amino acids. Because of the S
atom, the priority for the R group is higher than for the COOH group, which
is different than for all the other amino acids (where the R group priority
falls between the COOH and H).