Consider compounds A, B and C with following structural formulae A = CH_3 - CH_2 - CH_2 - CH_2 - CH_2 - OH B = CH_2 = CH - CH_2 - CH_2 - CH_3 C = HO - CH_2 - CH_2 - CH(OH) - CH_3 For the conversion of B from A, reagent (D) required is _________ and structural formula of product (E) obtained when C undergoes same reaction using excess reagent (D) is _________.
D. D E Conc. H_2SO_4 or H_3PO_4 CH_2 = CH - CH = CH_2
Compound A is pentan-1-ol (CH_3-CH_2-CH_2-CH_2-CH_2-OH) and Compound B is pent-1-ene (CH_2=CH-CH_2-CH_2-CH_3). The conversion of an alcohol to an alkene is a dehydration reaction, which requires an acidic dehydrating agent such as concentrated H_2SO_4 or H_3PO_4. Thus, reagent D is concentrated H_2SO_4 or H_3PO_4. Compound C is butane-1,3-diol (HO-CH_2-CH_2-CH(OH)-CH_3). When C is treated with excess dehydrating agent (reagent D), both hydroxyl groups undergo elimination (dehydration). The elimination of two water molecules yields a conjugated diene, which is highly stable due to resonance. The product E formed is 1,3-butadiene (CH_2=CH-CH=CH_2). Answer: D E Conc. H_2SO_4 or H_3PO_4 CH_2 = CH - CH = CH_2
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