91Ó°ÊÓ

(a) condenses in presence of phenyl hydrazine and ${\text{H}}^{+}$ to form$\text{cyclohexanone phenylhydrazone}$ .

$\text{reaction a}$

(b) DIBAL-H reduces ester ($\text{methyl cyclopent - 1 - enecarboxylate}$ ) directly to aldehyde ($\text{cyclopent - 1 - enecarbaldehyde}$ ) at dry ice temperature of about${\text{- 78}}^{\text{0}}\text{C}$ .

$\text{reaction b}$

(c) DIBAL-H reduces nitrile ($\text{cyclohexanecarbonitrile}$ ) to its corresponding aldehyde ( $\text{cyclohexanecarbaldehyde}$) . The initial reaction produces an aluminum complex which hydrolyzes in aqueous medium.

$\text{reaction c}$

(d) $\text{2 - cyclohexylacetyl chloride}$reacts with a Gilman reagent (lithiumdialkyl cuprate) forms a ketone ( $\text{1 - cyclohexylbut - 3 - en - 2 - one}$).

$\text{reaction d}$

(e) $\text{2 - methoxytetrahydro - 2H - pyran}$ on hydrolysis forms the products as $\text{5 - hydroxypentanal}$$\text{5 - hydroxypentanal}$ and methanol

$\text{reaction e}$

(f) Lithium tri-tert-butoxyaluminum hydride reduces the given acid chloride

($\text{2 - cyclohexylacetyl chloride}$ ) to an aldehyde ( $\text{2 - cyclohexylacetaldehyde}$).

$\text{reaction f}$

(g) $\text{Cyclohexanecarboxylic acid}$ reacts with ethyllithium fllowe dbu hydrolysis to form$\text{1 - cyclohexylprop - 2 - en - 1 - one}$.

$\text{reaction g}$

(h) $\text{(E) - but - 2 - en - 1 - ylidenetriphenylphosphorane}$combines with $\text{pentan - 3 - one}$$\text{1 - ethylcyclohexa - 1,3 - diene}$ to forms

$\text{reaction h}$

(i) $\text{benzo[d][1,3]dioxole}$ forms $\text{pyrocatechol}$ on hydrolysis

$\text{reaction i}$

(j) $\text{1 - (2 - (2 - aminoethyl)phenyl)ethanone}$ forms $\text{1 - methyl - 3,4 - dihydroisoquinoline}$on protonation followed by loss of water molecule.

$\text{reaction j}$