Finding products of the given reactions, considering regiochemistry where applicable.

Question

What would be the products for the following reactions, considering regiochemistry where applicable, whilst noting that some reactions may yield multple products.

a) (R)-(tert-butyl)cyclohex-1-ene with H₂/Pd

for b) to g) :

1-Buten-2-ylcyclopropane with

b) Br₂ in CH₂Cl₂

c) HBr in ether

d) H₂SO₄

e) H₂O / H₃PO₄ Catalyst, 250°C

f) 1.O₃ then 2.Zn, H₃O⁺, mild conditions

g)Reaction with KMnO₄ /H₃O⁺ under vigorous conditions

Answer 1

a) (R)-(tert-butyl)cyclohex-1-ene with H₂/Pd:

We have: (R)-(tert-butyl)cyclohexane with H- and H- on the same side and the opposite side of (R)-(tert-butyl) which is less sterically encumbered (but it change nothing because we can't have enantiomer or diastereoisomer because because there is already an H- on each carbon in the double bond.

b) 1-Buten-2-ylcyclopropane Br₂ in CH₂Cl₂:

We have an anti-addition of -Br so the products are: 1,2(R)-dibromobutan-2-ylcyclopropane and 1,2(S)-dibromobutan-2-ylcyclopropane in same quantity (racemic solution).

c) 1-Buten-2-ylcyclopropane HBr in ether:

The reaction proceeds as a typical electrophilic addition, with the bromine atom -Br attaching to the more substituted carbon of the alkene, following Markovnikov's rule, resulting in the formation of an alkyl bromide product; the ether solvent does not significantly affect the reaction mechanism itself. So we have:

2(R)-bromobutan-2-ylcyclopropane and 2(S)-bromobutan-2-ylcyclopropane in same quantity (racemic solution)...