Angular 6 best way to sequence functions that are not http oriented

I am not strong with RxJS so am looking for guidance on how best to chain a sequence of simple non http.get etc. functions in Angular so that they happen in a synchronous fashion.

E.g. what is the 'best' way to run these in sequence in a component?

  function1() {
    setTimeout(function(){ alert("Hello 1"); }, 3000);
  }

  function2() {
    setTimeout(function(){ alert("Hello 2"); }, 6000);
  }

  function3() {
    setTimeout(function(){ alert("Hello 3"); }, 1000);
  }

  function4() {
    setTimeout(function(){ alert("Hello 4"); }, 750);
  }