Nodejs convert expensive synchronous tasks to async series

In nodejs I have an expensive function such as:

function expensiveCode(){
  a.doExensiveOperation(1);
  b.doAnotherExensiveOperation(2);
  c.doADiffererentExensiveOperation(3);
  d.doExensiveOperation(4);
}

Such that each sub-function call has different parameters and therefore can't be done in a loop. I'd like to throttle this expensive function call so that each sub-call is done on nextTick such as:

function expensiveCode(){
    process.nextTick(function(){
        a.doExensiveOperation(1);
        process.nextTick(function(){
            b.doAnotherExensiveOperation(2);
            process.nextTick(function(){
                c.doADiffererentExensiveOperation(3);
                process.nextTick(function(){
                  d.doExensiveOperation(4);                 
                });
            });
        });
    });
}

That's obviously ugly, and if there are 20 lines of different operations will too hideous to even consider.

I've reviewed a number of libraries like "async.js" but they all appear to be expecting the called functions to be async - to have a callback function on completion. I need a simple way to do it without converting all my code to the 'callback when done' method which seems like overkill.