(1) In the epoxidation of cholesterol experiment, how will you know when the reaction has gone to completion?
(a) when 15 minutes has passed
(b) when a TLC of the reaction mixture shows 2 spots
(c) when a TLC of the reaction mixture shows only 1 spot and that spot corresponds to the product
(d) when the reaction mixture loses its orange color
(2) A common method for the prepartaion of epoxides, or oxiranes, is from the reaction of a peroxycarboxylic acid and what class of compounds:
(a) alkyl halides
(b) carboxylic acids
(c) aldohols
(d) alkenes
(3) When the reaction has gone to completion, the mixture contains the epoxycholesterol and 3-chloroperoxybenzoic acid. The mixture is loaded onto an alumina column and eluted with 30 mL of ether. Why don’t you have to collect and analyze fractions as you did in the Column Chromatography experiment?
(a) because it doesn't matter if the 3-chloroperoxybenzoic acid comes through the column because it will degrade anyway
(b) because the 3-chloroperoxy benzoic acid is very polar and sticks firmly to the column, never to elute with ether
(c) because it doesn't matter if the product is contaminated, since you will recrystallize it anyway
(d) because the 3-chloroperoxy benzoic acid will not show up on TLC
(4) On which side would the molecule below undergo epoxidation? Would the product be called alpha or beta?
(a) front side, alpha
(b) front side, beta
(c) back side, alpha
(d) back side, beta