Haloalkanes and Haloarenes - Class 12

Consider the electrophilic monochlorination of two isomeric tertiary amines, \textbf{X} (4-methyl-$N,N$-dimethylaniline) and \textbf{Y} (2-methyl-$N,N$-dimethylaniline), using \ce{Cl2} in glacial acetic acid at 298 K in the dark. Let $P_X$ and $P_Y$ be the major monochlorinated products of \textbf{X} and \textbf{Y}, respectively. Which of the following correctly identifies $P_X$ and $P_Y$?

An optically active haloalkane, (S)-2-chloro-1,1,1-trifluoropropane (\textbf{X}), is treated with an excess of diethylamine (\ce{Et2NH}) in methanol at 330 K in a sealed tube to yield a major organic product \textbf{Y}. Subsequently, \textbf{Y} is reacted with \ce{Cl2(aq)} in the presence of excess \ce{H2O(l)} to produce the major product \textbf{Z}. Identify the structure and IUPAC name of \textbf{Z}.

A chemist attempts to synthesize an azo dye starting from chlorobenzene via the following synthetic route:

Step 1: \ce{C6H5Cl} $\xrightarrow{\ce{HNO3, H2SO4}, 298\text{ K}}$ \textbf{P} (Major product)

Step 2: \textbf{P} $\xrightarrow{\ce{Sn / HCl}, \text{ then } \ce{NaOH}}$ \textbf{Q}

Step 3: \textbf{Q} $\xrightarrow{\ce{NaNO2, HCl}, 298\text{ K}}$ \textbf{R}

Step 4: \textbf{R} $\xrightarrow{\beta\text{-naphthol, NaOH}, 273\text{ K}}$ \textbf{S} (after mild acidification)

Identify the final outcome (\textbf{S}) of this synthetic sequence.

Consider the following reaction sequence starting with 4-chlorobenzoic acid:

$\text{4-chlorobenzoic acid} \xrightarrow[\text{(ii) } H_2O]{\text{(i) } CH_3CH_2Cl \text{ (1 eq.), anhydrous } AlCl_3 \text{, } \Delta} \text{P}$

$\text{P} \xrightarrow{SOCl_2 \text{, Pyridine, reflux}} \text{Q}$

$\text{Q} \xrightarrow[\text{(ii) } H_2O]{\text{(i) Toluene (excess), anhydrous } AlCl_3 \text{, 298 K}} \text{R}$

$\text{R} \xrightarrow[\text{(ii) } H_3O^+]{\text{(i) } KMnO_4 \text{, } KOH \text{, } \Delta} \text{S}$

Identify the major organic product \textbf{S}.

Compound $P$ is 1,1,1-trichloro-2-(4-chlorophenyl)-3-nitropropane. \begin{itemize} \item \textbf{Reaction 1:} $P$ is treated with $Sn/HCl$ followed by basification to yield major product $X$. \item \textbf{Reaction 2:} $P$ is treated with excess $LiAlH_4$ in dry THF followed by aqueous workup to yield major product $Y$. \end{itemize} Identify $X$ and $Y$.

Consider the following reaction sequence:

$\text{Naphthalen-2-ol} \xrightarrow[\text{120 }^\circ\text{C, 4-7 atm}]{\text{1. } \ce{NaOH, CO2} \text{ 2. } \ce{H3O+}} \textbf{X} \text{ (Major Product)}$

$\textbf{X} \xrightarrow[\text{pH = 9-10, 0-5 }^\circ\text{C}]{\ce{Ph-N2+ Cl-}} \textbf{Y} \text{ (Major Product)}$

Identify \textbf{X} and \textbf{Y}.

Consider the following reaction sequence starting with 1-chloro-2-methoxybenzene (Compound \textbf{A}):

1. \textbf{A} $\xrightarrow{\ce{KNH2}, \text{ liq. } \ce{NH3}, 233 \text{ K}}$ \textbf{B} (Major Product)
2. \textbf{B} $\xrightarrow[\text{2. } \ce{CuCN}, \ce{KCN}, \Delta]{\text{1. } \ce{NaNO2}, \ce{HCl}, 273 \text{ K}}$ \textbf{C}
3. \textbf{C} $\xrightarrow[\text{2. } \ce{H3O+}]{\text{1. } \ce{CH3MgBr} \text{ (excess), dry ether}}$ \textbf{D}
4. \textbf{D} $\xrightarrow[\text{2. } \ce{H3O+}]{\text{1. } \ce{I2}, \ce{NaOH}, \Delta}$ \textbf{E} (Major Product) + $\ce{CHI3}$

Identify the final product \textbf{E}.

Consider the following reaction sequence for 1-bromo-4-nitrobenzene:

\textbf{Pathway I:} Treatment with \ce{Sn / HCl} followed by basification with aqueous \ce{NaOH} yields major product $P$.

\textbf{Pathway II:} Treatment with excess \ce{LiAlH4} in dry ether at reflux, followed by careful aqueous workup yields major product $Q$.

Identify the major products $P$ and $Q$.

Compound \textbf{P} (3-hydroxybenzoic acid) is treated with excess aqueous bromine to yield a tribrominated aromatic compound \textbf{Q}. \textbf{Q} is then subjected to two separate reactions: Reaction 1: \textbf{Q} is heated with excess $\ce{CH3OH}$ and a catalytic amount of concentrated $\ce{H2SO4}$ to give \textbf{R}. Reaction 2: \textbf{Q} is treated with one equivalent of diazomethane ($\ce{CH2N2}$) in ether to give \textbf{S}. Identify \textbf{R} and \textbf{S}.

Consider the following reaction sequence starting from 3-methylaniline: $\text{3-Methylaniline} \xrightarrow{\text{1. } PhSO_2Cl, \text{ pyridine}} \textbf{P} \xrightarrow{\text{2. } Br_2, CH_3COOH} \textbf{Q} \xrightarrow{\text{3. } 70\% \text{ } H_2SO_4, \Delta} \textbf{R}$ $\textbf{R} \xrightarrow{\text{4. } NaNO_2, HCl, 273 \text{ K}} \textbf{S} \xrightarrow{\text{5. } CuCN, KCN, \Delta} \textbf{T} \xrightarrow{\text{6. } \text{DIBAL-H (1 eq), } -78^\circ\text{C, then } H_2O} \textbf{U}$ Identify the major product $\textbf{U}$.

Compound \textbf{P} (4-fluoro-3,5-dimethyl-2-nitrobenzoyl chloride) is treated with 1 equivalent of $\ce{CH3ONa}$ in $\ce{CH3OH}$ at $-20^\circ\text{C}$ to yield compound \textbf{Q}. Subsequently, \textbf{Q} is heated with excess $\ce{CH3NH2}$ in a sealed tube at $150^\circ\text{C}$ to yield the major product \textbf{R}. Identify \textbf{R}.

Consider the compound 1-bromo-2-fluorobenzene. It is subjected to two distinct reaction conditions to yield major organic products $\textbf{P}$ and $\textbf{Q}$:

Condition I: $\ce{NaNH2}$ (3 equivalents), $\ce{NH3 (l)}$, $240\text{ K} \longrightarrow \textbf{P}$ Condition II: $\ce{NaOMe}$ (excess), DMSO, $373\text{ K} \longrightarrow \textbf{Q}$

Identify the major products $\textbf{P}$ and $\textbf{Q}$.

An organic compound \textbf{X} (3-fluoro-4-nitroaniline, $1.0 \text{ mol}$) is subjected to the following sequential one-pot reaction:\n\n\textbf{Step 1:} Treated with Phenol ($1.0 \text{ mol}$) and \ce{NaOH} ($3.0 \text{ mol}$) in DMSO at $100^\circ\text{C}$.\n\textbf{Step 2:} The resulting mixture is cooled to $0-5^\circ\text{C}$, followed by the addition of \ce{NaNO2} ($1.0 \text{ mol}$) and \ce{HCl} ($3.0 \text{ mol}$).\n\nAssuming complete conversion in Step 1, what is the major organic product isolated at the end of Step 2?

The heterocyclic compound 4-chloro-2-hydroxypyridine ($\textbf{X}$) exhibits pronounced solvent-dependent reactivity.

When $\textbf{X}$ is treated with piperidine in anhydrous toluene at $80^\circ\text{C}$, it rapidly undergoes a substitution reaction to form product $\textbf{P}$.

Conversely, when $\textbf{X}$ is treated with piperidine in water at $80^\circ\text{C}$, the substitution is exceptionally slow. However, treating this aqueous solution of $\textbf{X}$ with $\ce{Br_2}$ (1 equivalent) at $25^\circ\text{C}$ results in the rapid formation of a mono-brominated major product $\textbf{Q}$.

Which of the following best describes the dominant tautomer in each solvent, its effect on reactivity, and the structure of $\textbf{Q}$?

Consider the following reaction sequence:

$\ce{2-Bromo-N,N-dimethylaniline ->[NaNH2 (excess)][NH3(l), 239 K] P ->[NaNO2, HCl][273 K] Q ->[Phenol, NaOH][273 K] R (Major Product)}$

Identify the major product $\ce{R}$.

Compound $\textbf{X}$ is \ce{methyl 2-(2-bromophenyl)acetate}. It is subjected to two distinct reaction pathways to test functional group compatibility and reactive intermediates:

\textbf{Pathway A:} $\textbf{X}$ is treated with excess \ce{NaNH2} in liquid \ce{NH3} at $240\text{ K}$, followed by careful neutralization, to yield the major product $\textbf{P}$.

\textbf{Pathway B:} $\textbf{X}$ is first treated with excess \ce{LiAlH4} in dry THF at $298\text{ K}$ followed by aqueous workup to give intermediate $\textbf{Y}$. $\textbf{Y}$ is then treated with excess \ce{NaNH2} in liquid \ce{NH3} at $240\text{ K}$, followed by neutralization, to yield the major product $\textbf{Q}$.

Identify the structures of $\textbf{P}$ and $\textbf{Q}$.

Consider the following reaction sequence:

\ce{2-Bromoanisole ->[NaNH2][liq. NH3, 240 K] \textbf{A} (Major)}

\ce{\textbf{A} ->[NaNO2, HCl][273-278 K] \textbf{B}}

\ce{\textbf{B} ->[Phenol, NaOH][pH 9-10, 273-278 K] \textbf{C} (Major)}

Identify the IUPAC name of the major product \textbf{C}.

Consider the reaction of (4R)-1-(2-bromophenoxy)-4-chloropentane with excess sodium amide (\ce{NaNH2}) in liquid ammonia at 195 K. Identify the major organic product formed.

An optically pure sample of (1S)-1-bromo-2,2-dimethyl-1-phenylpropane is heated with a concentrated solution of \ce{NaOCH3} in \ce{CH3OH}. The reaction yields 1-methoxy-2,2-dimethyl-1-phenylpropane. Which of the following correctly describes the stereochemical outcome of this product and the underlying kinetic rationale?

An optically active alkyl halide, (2S, 3R)-2-bromo-3-phenylbutane, is treated with a concentrated solution of sodium ethoxide (\ce{NaOEt}) in ethanol at $80^\circ\text{C}$. Which of the following represents the major organic product formed?

An aqueous solution of D-glucose at $298\text{ K}$ is at mutarotation equilibrium, consisting of $36\%$ $\alpha$-D-glucopyranose and $64\%$ $\beta$-D-glucopyranose (open-chain form $\approx 0.02\%$). At $t=0$, a large excess of a trapping reagent is added. This reagent reacts instantaneously and irreversibly \textit{exclusively} with the open-chain aldehyde form of D-glucose. Let $k_\alpha$ and $k_\beta$ be the first-order rate constants for the ring-opening of the $\alpha$ and $\beta$ anomers, respectively, where $k_\alpha \neq k_\beta$. Which of the following statements correctly describes the kinetic decay of the total unreacted cyclic glucose concentration, $[G]_{total}$, and the evolution of the $\alpha/\beta$ ratio during the reaction?

An optically inactive compound $\textbf{X}$ with the IUPAC name $(3R, 4S, 5R, 6S)-3,6-dimethyl-3,6-diphenyloctane-4,5-diol$ is subjected to oxidative cleavage using an excess of periodic acid (\ce{HIO4}) in an aqueous medium at 298 K. Which of the following statements correctly describes the stereochemical nature of the resulting organic product(s)?

An enantiomerically pure sample of $(2S)$-2-bromobutane is treated with a solution of potassium \textit{tert}-butoxide in \textit{tert}-butanol at $350\text{ K}$. Which of the following best describes the major product formed and its optical activity?

An organic chemist attempts to synthesize the ether 2-methoxy-2,3-dimethylbutane using two different Williamson ether synthesis pathways:

Pathway P: Reaction of 2-chloro-2,3-dimethylbutane with $\ce{NaOCH3}$ in $\ce{CH3OH}$ at $330\text{ K}$. Pathway Q: Reaction of sodium 2,3-dimethyl-2-butoxide with $\ce{CH3Cl}$ in DMF at $298\text{ K}$.

Which of the following correctly identifies the major organic products formed in Pathway P and Pathway Q, respectively?

Consider the following reaction sequence:

1,2-dichloro-4-nitrobenzene $\xrightarrow[\text{65}^\circ\text{C}]{\text{NaOCH}_3 \text{ (1 equiv), CH}_3\text{OH}}$ $\text{P}$

$\text{P} \xrightarrow[\text{2. NaOH(aq)}]{\text{1. Sn, HCl, }\Delta}$ $\text{Q}$

$\text{Q} \xrightarrow[\text{2. CuCN, KCN, }\Delta]{\text{1. NaNO}_2\text{, HCl, 273 K}}$ $\text{R}$

$\text{R} \xrightarrow[\text{2. H}_3\text{O}^+\text{, }\Delta]{\text{1. CH}_3\text{MgBr (1 equiv), dry ether}}$ $\text{S}$

Identify the major product $\text{S}$.

Consider the following two-step reaction sequence:

Step 1: $\text{(2S,3R)-2-bromo-3-deuteriobutane} + \ce{NaI} \xrightarrow[\text{298 K}]{\text{dry acetone}} \text{Major Product P}$

Step 2: $\text{Product P} + \ce{NaOEt} \xrightarrow[\text{350 K}]{\ce{EtOH}} \text{Major Product Q}$

Identify the major product Q.

An equimolar mixture of bromocyclohexane and 3,3-dimethylbut-1-yne is dissolved in dry THF. To this solution, 1.0 equivalent of magnesium turnings is added, and the mixture is stirred at $298 \text{ K}$ until the magnesium is completely consumed. Subsequently, 1.0 equivalent of acetaldehyde ($\ce{CH3CHO}$) is added to the reaction mixture, followed by a standard acidic workup ($\ce{H3O+}$). Identify the major organic product isolated from this sequence.

An alkyl halide, $\ce{CH3-C(CH3)2-CH(Br)-CH3}$ (3-bromo-2,2-dimethylbutane), is subjected to two distinct reaction conditions:

Condition I: $\ce{t-BuOK}$ in $\ce{t-BuOH}$ at $80^\circ\text{C} \rightarrow$ Major Product $\mathbf{P}$ Condition II: $\ce{AgNO3}$ in $\ce{EtOH}$ at $80^\circ\text{C} \rightarrow$ Major Product $\mathbf{Q}$

Identify the major organic products $\mathbf{P}$ and $\mathbf{Q}$.

Consider the reaction of (2-methoxypropan-2-yl)cyclobutane with 1 equivalent of anhydrous \ce{HI} at 298 K. Identify the major organic product formed.

Consider the solvolysis of 2-bromo-3,3-dimethylbutane in $\text{H}_2\text{O}$ at $80^\circ\text{C}$. Identify the major organic product formed.

Consider the reaction of ethyl 5-bromo-4,4-dimethyl-3-oxohexanoate with exactly one equivalent of ethylmagnesium bromide ($\ce{EtMgBr}$) in dry ether at 298 K. The resulting intermediate is then carefully quenched with an excess of $\ce{D_2O}$. What is the major organic product (P) formed?

Substrate: $\ce{CH3-CH(Br)-C(CH3)2-C(=O)-CH2-CO2Et}$

Optically pure $(S)$-2-chloro-3-methylbutane is subjected to solvolysis in glacial acetic acid ($\ce{CH3COOH}$) at $298\text{ K}$. The reaction yields a major rearranged substitution product $\textbf{P}$ and a minor unrearranged substitution product $\textbf{Q}$. Which of the following best describes the stereochemical outcome of $\textbf{Q}$ and the primary mechanistic phenomenon responsible for it?

An optically pure sample of (2S)-2-bromo-3,3-dimethylbutane is heated in anhydrous methanol at $60^\circ \text{C}$. The major substitution product $P$ is isolated. Which of the following statements correctly describes the structure of $P$, its stereochemistry, and the dominant mechanistic pathway?

Consider the reaction of (2S, 3S)-2,3-dimethyl-2-phenyloxirane with excess methanol in the presence of catalytic $H_2SO_4$ at 298 K. Identify the major product(s) and the dominant mechanism governing the stereochemical outcome at the site of nucleophilic attack.

Consider the reaction of (2S)-2-bromobutane with $1.0\text{ M } \ce{NaOEt}$ at $330\text{ K}$. When performed in ethanol ($\ce{EtOH}$), the activation energy for the $\text{S}_\text{N}2$ pathway is $E_{a,1}$ and for the $\text{E}2$ pathway is $E_{a,2}$. When the solvent is switched to dimethyl sulfoxide (DMSO) under identical conditions, the activation energy for the $\text{S}_\text{N}2$ pathway is $E_{a,3}$. Identify the major product formed in $\ce{EtOH}$ and the correct thermodynamic relationship between the activation energies.

Consider the following two independent reactions performed at $298\text{ K}$:

Reaction I: $(2R, 4S)\text{-2-bromo-4-methylhexane}$ is treated with $1\text{ equivalent}$ of $\ce{NaCN}$ in $\ce{DMSO}$ to yield the major product $\mathbf{P}$.

Reaction II: $(4S)\text{-4-methylhexan-2-one}$ is treated with excess $\ce{HCN}$ in the presence of a catalytic amount of $\ce{KCN}$ to yield product $\mathbf{Q}$.

Which of the following correctly describes the stereochemical nature of products $\mathbf{P}$ and $\mathbf{Q}$?

An organic chemist intends to synthesize the sterically hindered ether, 2-isopropoxy-2-methylpropane (isopropyl tert-butyl ether), and attempts two distinct Williamson ether synthesis pathways at $340\text{ K}$:

Pathway I: Reaction of 2-bromo-2-methylpropane with sodium isopropoxide in isopropanol. Pathway II: Reaction of 2-bromopropane with sodium 2-methylpropan-2-olate in 2-methylpropan-2-ol.

Let $X$ and $Y$ be the major organic products formed in Pathway I and Pathway II, respectively. Which of the following correctly identifies $X$, $Y$, and the most viable alternative method to synthesize the target ether in high yield?

Consider the reaction of the following two bromo-ketones with 1 equivalent of $\ce{NaCN}$ in anhydrous DMF at 298 K:

Reaction 1: $\text{6-bromohexan-3-one} + \ce{NaCN} \xrightarrow{\text{DMF}} \text{Major Product } \textbf{P}$

Reaction 2: $\text{6-bromo-2,2,4,4-tetramethylhexan-3-one} + \ce{NaCN} \xrightarrow{\text{DMF}} \text{Major Product } \textbf{Q}$

Identify the correct IUPAC names for the major products $\textbf{P}$ and $\textbf{Q}$.

Consider the solvolysis of (2S, 3S)-2-chloro-3-(methylthio)butane in an aqueous medium at 298 K. The reaction proceeds exclusively via a cyclic intermediate due to Neighboring Group Participation (NGP). Identify the major stereoisomeric product(s) formed.

An organic compound $A$ (\ce{C8H5NO2}) is treated with exactly one equivalent of ethanolic \ce{KOH} to form a salt $B$, which is isolated and dried. $B$ is then reacted with one equivalent of 2-bromo-2-methylpropane in anhydrous dimethyl sulfoxide (DMSO) at $80^\circ\text{C}$. The reaction yields a gaseous hydrocarbon $C$ and a nitrogen-containing organic compound $D$ as the major products.

Let $x$ be the number of $sp^3$ hybridized carbon atoms in $D$. Let $y$ be the number of hyperconjugative $\alpha$-hydrogen atoms in $C$.

What is the value of $2x + y$?

Consider the following substrates undergoing nucleophilic substitution with $\ce{NaOCH3}$ in $\ce{CH3OH}$ at 298 K:

(P) 1-chloro-2,4-dinitrobenzene (Q) 1-chloro-3,5-dimethyl-2,4-dinitrobenzene (U) 1-chloro-4-nitrobenzene (R) 1-bromo-2,2-dimethylpropane (S) 1-bromobutane

Let $E_{a,P}$, $E_{a,Q}$, and $E_{a,U}$ be the activation energies for the $\text{S}_\text{N}\text{Ar}$ reactions of P, Q, and U respectively. Let $E_{a,R}$ and $E_{a,S}$ be the activation energies for the $\text{S}_\text{N}2$ reactions of R and S respectively.

Which of the following correctly orders the activation energies, reflecting the dominant transition state electronic and steric effects?

Consider the enantiomerically pure alkyl halide, (S)-2-bromo-3-methylbutane (\textbf{A}). It undergoes three distinct parallel reaction sequences:

Reaction I: \textbf{A} is treated with $\ce{NaCN}$ in anhydrous DMSO to yield major product \textbf{D}.

Reaction II: \textbf{A} is treated with potassium tert-butoxide ($\ce{t-BuOK}$) in tert-butanol at $70^\circ\text{C}$ to yield major product \textbf{B}. \textbf{B} is then subjected to hydroboration-oxidation ($\ce{B2H6/THF}$ followed by $\ce{H2O2/NaOH}$) to yield \textbf{E}.

Reaction III: \textbf{A} is treated with sodium ethoxide ($\ce{NaOEt}$) in ethanol at $70^\circ\text{C}$ to yield major product \textbf{C}. \textbf{C} is then subjected to oxymercuration-demercuration ($\ce{Hg(OAc)2/H2O}$ followed by $\ce{NaBH4}$) to yield \textbf{F}.

Identify the correct IUPAC names and stereochemistry for \textbf{D}, \textbf{E}, and \textbf{F}.

Consider the dehydration of 3,3-dimethylbutan-2-ol under two different sets of conditions:

Condition I: Treatment with $\ce{POCl3}$ in pyridine at $0^\circ\text{C}$ to give major product $P$. Condition II: Heating with $85\% \ \ce{H3PO4}$ at $150^\circ\text{C}$ to give major product $Q$.

Identify the major products $P$ and $Q$.

Consider the elimination reactions of (2S,3S)-2-bromo-3-methylpentane under two different sets of conditions:

Reaction I: $t$-BuOK in $t$-BuOH at 323 K $\rightarrow$ Major product $P$ Reaction II: $t$-BuOK in DMSO at 323 K $\rightarrow$ Major product $Q$

Identify the major products $P$ and $Q$.

An alkyl halide $X$ ($C_5H_{11}Br$) is subjected to dehydrohalogenation under two different sets of conditions:

Reaction 1: $X \xrightarrow{NaOEt / EtOH, \ 350 \text{ K}}$ $P$ (Major) Reaction 2: $X \xrightarrow{KOtBu / t-BuOH, \ 350 \text{ K}}$ $Q$ (Major)

Reductive ozonolysis of $P$ yields a mixture of two carbonyl compounds; one gives both a positive Tollens' test and a positive iodoform test, while the other gives a negative Tollens' test. Reductive ozonolysis of $Q$ yields two carbonyl compounds, one of which is a gas at $298 \text{ K}$ and the other gives a positive iodoform test.

What is the absolute difference in the number of hyperconjugative $\alpha$-hydrogens between the major products $P$ and $Q$?

Consider the reaction of 2,2-dimethyl-3,3-dideuterooxirane with excess potassium \textit{tert}-butoxide in \textit{tert}-butanol at $80^\circ\text{C}$, followed by mild aqueous workup. Which of the following represents the major organic product?

An organic compound \textbf{X}, 1-(2-bromopropyl)-2,4-dimethoxybenzene, is treated with Potassium fluoride ($\ce{KF}$) and [2.2.2]cryptand in anhydrous benzene at $350\text{ K}$.

$\textbf{X} + \ce{KF} \xrightarrow[\text{Benzene, } 350\text{ K}]{\text{[2.2.2]cryptand}} \text{Major Product (P)}$

Identify the major product \textbf{P}.

Consider the following alkyl bromides subjected to the Finkelstein reaction (treatment with $NaI$ in dry acetone at $298\text{ K}$): (I) 1-Bromobutane (II) 2-Bromobutane (III) 1-Bromo-2,2-dimethylpropane (IV) 1-Bromobicyclo[2.2.1]heptane

Identify the correct decreasing order of their initial rates of reaction.

Diphenyldibromomethane ($\ce{Ph2CBr2}$) is treated with an excess of Mercury(I) fluoride ($\ce{Hg2F2}$) in anhydrous toluene at 298 K in the dark. Considering the redox properties of the reagent and the stability of the intermediates, what is the major organic product formed?

An optically active alkyl halide, (2$S$, 3$R$)-2-bromo-3-methylpentane, is subjected to two different sets of reaction conditions:

Condition I: Treatment with 1.0 equivalent of \ce{NaI} in anhydrous acetone at 298 K yields major product P. Condition II: Treatment with 1.0 equivalent of \ce{NaOMe} in methanol at 330 K yields major product Q.

Which of the following correctly identifies the stereochemistry of P and Q?