Ruby odd number of arguments for hash error

case look
  when 'side'
        hash1 = {
            'num' => 5,
            'style' => 'sideStyle',
        }

  when 'front'
        hash1 = {
            'num' => 8,
            'style' => 'frontStyle',
        }

  when 'back'
        hash1 = {
            'num' => 4,
            'style' => 'backStyle',
            'special' => 'yes',
        }

  else
        hash1 = {
            'num' => 2,
            'style' => 'noStyle',
        }
  end

  myStyle = Hash[hash1]

My piece of code looks like this.

when I run this code I get "odd number of arguments for Hash".

is this the correct way to from an hash? could someone please help me how to get it resolved.