A hydroxy acid on heating gives a 5-membered lactone. The acid is

Question

A hydroxy acid on heating gives a 5-membered lactone. The acid is (A) CH 2 OHCH 2 CH 2 COOH (B)  CH3CHOHCH2COOH  (C)  CH3CH2CHOHCOOH  (D)  CH3CHOHCHOHCOOH

Tardigrade Admin · Accepted Answer

&gamma; or δ -hydroxy acids, on heating, give lactones, having same number of carbon atoms as the parent acid. Thus, overset&gamma;C H 2 OH oversetβ C H 2 oversetα C H 2 COOH gives five membered lactone. underset overset|OHC H 2 CH 2 CH 2 underset overset|OHC = O ->[Δ][-H2O]

Q. A hydroxy acid on heating gives a $5$ -membered lactone. The acid is

$C H_{2} O H C H_{2} C H_{2} COO H$

$C H_{3} C H O H C H_{2} COO H$

$C H_{3} C H_{2} C H O H COO H$

$C H_{3} C H O H C H O H COO H$

$γ$ or $δ$ -hydroxy acids, on heating, give lactones, having same number of carbon atoms as the parent acid.
Thus, $C γ H_{2} O H C β H_{2} C α H_{2} COO H$ gives five membered lactone.
$O H ∣ C H_{2} C H_{2} C H_{2} O H ∣ C = O Δ - H_{2} O$

Q. A hydroxy acid on heating gives a 5-membered lactone. The acid is

CH2​OHCH2​CH2​COOH

CH3​CHOHCH2​COOH

CH3​CH2​CHOHCOOH

CH3​CHOHCHOHCOOH