Sharpless epoxidation NaOH, CH;SH OH (+)-DET H,0, (CH2);COH .SCH5 х он

A compound with formula C8H12 reacts with 2 molar equiv of H₂ to yield a cycloalkane. By treatment of this compound with acidic KMnO4, a dicarboxylic acid, HOOCCH2CH2COOH is obtained. What is the structure of this compound? (A) (B) (C) (D)

PGF 2a is a prostaglandin, a group of compounds that are responsible for inflammation (Section 19.6). (a) How many tetrahedral stereogenic centers does PGF 2a contain? (b) How many double bonds can exist as cis and trans isomers? (c) Considering both double bonds and tetrahedral stereogenic centers, what is the maximum number of stereoisomers that can exist for PGF20? OH HO -CH₂CH=CH(CH₂)3COOH CH=CHCH(OH)(CH₂)4CH3 PGF₂α

3 A compound A with a molecular formula CH3O is oxidised with acidified potassium dichromate(VI) to form a liquid B. B reacts with hydrogen cyanide to form a compound C that contains four carbon atoms. Draw the structures of compounds A, B and C. 4 An alkene D with a molecular formula C3H, can be converted into an alcohol E. This alcohol is oxidised to form a compound F, which does not give a silver mirror with Tollens' reagent. Draw the structures of compounds D, E and F.

Sharpless epoxidation of allylic alcohol X forms compound Y. Treatment of Y with NaOH and C6H5SH in an alcohol–water mixture forms Z. Identify the structure of Y and draw a mechanism for the conversion of Y to Z. Account for the stereochemistry of the stereogenic centers in Z. Z has been used as an intermediate in the synthesis of chiral carbohydrates.

Compound A, C₁1 H160, was found to be an optically active alcohol. Despite its apparent unsaturation, no hydrogen was absorbed on catalytic reduction over a Pd/C catalyst. On treatment of A with dilute H₂SO4, dehydration occurred and an optically inactive alkene B, C₁₁H₁4 was produced as the major product. Alkene B, on ozonolysis, gave two products. Product C, C7H6O, was shown to be an aldehyde while product D, C4H8O, was shown to be a ketone. Draw the structure of compound C. • You do not have to consider stereochemistry. • You do not have to explicitly draw H atoms. • In cases where there is more than one answer, just draw one.

In addition to more highly fluorinated products, fluorination of 2-methylbutane yields a mixture of compounds with the formula C5H10F2. Draw the structures of all the isomers with the formula C5H10F2 that would be produced and label with a star all the chiral centers present in their structures.

Compound A, CH10, was found to be an optically active alcohol. Despite its apparent unsaturation, no hydrogen was absorbed on catalytic reduction over a Pd/C catalyst. On treatment of A with dilute H,SO, dehydration occurred and an optically inactive alkene B, CH4 was produced as the major product. Alkene B, on ozonolysis, gave two products. Product C, C,H,0, was shown to be an aldehyde while product D, CHg0, was shown to be a ketone. Draw the structure of compound C. • You do not have to consider stereochemistry. You do not have to explicitly draw H atoms. In cases where there is more than one answer, jtust draw one.

2. Show how 1-butanol can be converted into the following compounds: (a) (b) CN

A chemist synthesized compound X as a racemic mixture. When the ketone group in X was enzymatically reduced to the corresponding alcohol, a 100% yield was obtained of the product shown below. Choose the statement that best describes this result. ОН enzyme C;H1 `OCH,CH; pH 4.0 C3H1 `OCH,CH3 ОН ÕH X (racemic) (100% yield) One enantiomer of compound X reacts quickly with the enzyme. The other enantiomer of compound X is unreactive, but rapidly equilibrates with the reactive enantiomer under the reaction conditions. Since compound X was racemic, it makes sense that only a single product was obtained. O The product is a meso compound, so either enantiomer of compound X gives the same product. One enantiomer of compound X reacts quickly with the enzyme, while the other enantiomer of compound X remains unchanged.