[racket] macro pattern problem

Hello all,

I want to quote every even and evaluate every odd variable of the input 
and assemble everything in a list.
So I wrote the following macro to do it:

(define-syntax quote-even
   (syntax-rules ()
     [(quote-even att val ...)
      (list 'att val ...)]))

But in the resulting list, only the very first attribute is quoted:

(syntax->datum
  (expand-once
   '(quote-even a 10 b 20 c 30)))

 > (list 'a 10 b 20 c 30)

(quote-even a 10 b 20 c 30)
 > b: undefined;


Is there a way to do do it?

Cheers,
Peter Samarin