Organic Chemistry Exam 1 Review
Review Packet for midterm 1
10/2/2013
Nikki Stefanko & Stephanie Ventura
24 1. Cortisol is a steroid hormone produced by the adrenal cortex that is released in response to stress and a low level of blood glucocorticoids.
OH
O
OH
HO
H
H
O
cortisol
H
a. Please fill in the table below: Molecular formula_____________________________ I-‐value (index of unsaturation, hydrogen deficiency)________ Number of: pi bonds______ sp3 carbons______
sp2 carbons______ sp carbons_______ no. of non-‐bonding pairs of electrons_____ aldehydes_____
esters_____ alcohols_____ amines_____ amides_____
ethers_____ carboxylic acids_____ aromatic groups_____ chiral centers_____ maximum no. of stereoisomers_____ b. Label each chiral center with an asterisk. (graded right – ½ wrong) Assign R or S to one AND ONLY ONE chiral center. c. Suppose the natural isomer of cortisol has a specific rotation of (+) 700˚. Suppose you have a mixture of the natural isomer and its enantiomers that gives an observed rotation of (-‐) 350˚. Which enantiomers is in excess? (+) or (-‐) Calculate the enantiomeric excess.
10/2/2013
Nikki Stefanko & Stephanie Ventura
24 1. Cortisol is a steroid hormone produced by the adrenal cortex that is released in response to stress and a low level of blood glucocorticoids.
OH
O
OH
HO
H
H
O
cortisol
H
a. Please fill in the table below: Molecular formula_____________________________ I-‐value (index of unsaturation, hydrogen deficiency)________ Number of: pi bonds______ sp3 carbons______
sp2 carbons______ sp carbons_______ no. of non-‐bonding pairs of electrons_____ aldehydes_____
esters_____ alcohols_____ amines_____ amides_____
ethers_____ carboxylic acids_____ aromatic groups_____ chiral centers_____ maximum no. of stereoisomers_____ b. Label each chiral center with an asterisk. (graded right – ½ wrong) Assign R or S to one AND ONLY ONE chiral center. c. Suppose the natural isomer of cortisol has a specific rotation of (+) 700˚. Suppose you have a mixture of the natural isomer and its enantiomers that gives an observed rotation of (-‐) 350˚. Which enantiomers is in excess? (+) or (-‐) Calculate the enantiomeric excess.