Draw the structures of organic compounds A and B. Indicate stereochemistry where applicable. 
H C C H 4.1 NaNH7  2.)CH3CH2CH2Br ( 1 equiv.) 

H2O, 
Inn • 
A.) 
112 Lindlar eat. V 
B.) 
 

1.

Explanation | Common mistakes | Hint for next step

Ethyne which is a terminal alkyne reacts with sodamide to give acetylides which on reaction with haloalkane produce higher alkyne which is pent-1-yne.

2.

Explanation | Common mistakes

The hydrogenation of alkynes can be easily carried out using deactivated catalysts such as Lindlar's catalyst to produce cis alkene. The Lindlar's catalyst Pd/CACO3  in lead acetate poisoned with a small amount of quinoline. The acid catalysed reaction of water with alkenes results in the formation of alcohol. The alcohol formed here is 2-pentanol. The addition of water molecule takes place according to Markonikov's rule which states that highly substituted alkenes are predominantly formed.

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