The question has already been answered, but I'd like to point out that even if it were possible, \%hash{'key'} wouldn't be working. You want a single element, a scalar, so it'd be \$hash{'key'} instead.

Let's cheat!

If you want the references in the hash assignment for readability, and don't use anonymous subs in it, you could abuse those:

%hash = (
    foo => 'bar',
    bar => sub { 'foo' }
);

(ref() eq 'CODE') && $_ = \$hash{ $_->() } for values %hash;
[download]

Same goes for any type of reference. So if you don't use anonymous arrays, you could use:

%hash = (
    foo => 'bar',
    bar => [ 'foo' ]
);

(ref() eq 'ARRAY') && $_ = \$hash{ $_->[0] } for values %hash;
[download]

You could of course cheat using some common prefix of which you're sure not to use it for any other purpose:

%hash = (
    foo => 'bar',
    bar => 'REF:foo'
);

/^REF:(.+)/ and $_ = \$hash{$1} for values %hash;
[download]

Or just replace the hash assignment with a lot of key assignments:

%hash = ();
for (
    [ foo => 'bar' ],
    [ bar => \$hash{foo} ]
) {
    $hash{ $_->[0] } = $_->[1];
}
[download]

Or use a temporary hash:

%hash = ();
%temp = (
    foo => 'bar',
    bar => \$hash{foo}
);

$hash{$_} = $temp{$_} for keys %temp;
[download]

BTW: I'm not really being serious.

++ vs lbh qrpbqrq guvf hfvat n ge va Crey :)
Nabgure bar vs lbh qvq fb jvgubhg ernqvat n znahny svefg.
-- vs lbh hfrq OFQ pnrfne ;)
    - Whreq