Four alkenes are described with the geometry stated. Which of them have the $E$ configuration?

A $ClCH X_{2} - C (CH X_{3}) = CH - CD X_{3}$ with $ClCH X_{2}$ and $CD X_{3}$ on opposite sides
B $CH X_{3} CH X_{2} - C (CD X_{3}) = CH - CH X_{3}$ with $CD X_{3}$ and the terminal $CH X_{3}$ on opposite sides
C $(CH X_{3}) X_{3} C - C (C X_{6} H X_{5}) = N - OH$ with $OH$ and the phenyl ring on the same side
D $(CH X_{3}) X_{3} C - C (CH = CH X_{2}) = CH - CH X_{3}$ with the vinyl group and the terminal $CH X_{3}$ on the same side

Answer: A, D

A: tert-butyl

(C, C, C)

outranks vinyl

(C, C, H)

. Vinyl is cis to the methyl, so tert-butyl is trans:

E

. B:

ClCH X_{2}

(Cl, H, H)

outranks

CH X_{3}

;

CD X_{3}

outranks

H

; they are trans:

E

. C: ethyl

(C, H, H)

outranks

CD X_{3}

; if

CD X_{3}

is trans to the methyl, ethyl is cis:

Z

. D: phenyl outranks tert-butyl and

OH

outranks the lone pair;

OH

cis to phenyl:

Z

. Correct: A and B.