Question

How can 2-propyn-1-ol be made from ethane and formaldehyde?

Answer 1

How about this sequence?

Explanation:

`"CH"_3"CH"_3 stackrelcolor(blue)("Br"_2//hνcolor(white)(m))(→) "CH"_3"CH"_2"Br"`

`"CH"_3"CH"_2"Br" stackrelcolor(blue)("KO"t"Bu"color(white)(m))(→)"CH"_2"=CH"_2`

`"CH"_2"=CH"_2 stackrelcolor(blue)("Br"_2color(white)(m))(→) "BrCH"_2"CH"_2"Br"`

`"BrCH"_2"CH"_2"Br" stackrelcolor(blue)("3LDA"color(white)(m))(→) "H-C≡C:"^"-" "Li"^+`

`"H-C≡C:"^"-" "Li"^+ stackrelcolor(blue)("1. H"_2"C=O"color(white)(m))→ "H-C≡C-CH"_2"OH"`
`color(white)(mmmmmmll) stackrelcolor(blue)("2. H"_3"O"^+)(color(white)(m)`