Tengo el siguiente escenario:

 async function asyncfunc1() { var request = new XMLHttpRequest(); request.open('GET', requestURL, false); request.responseType = 'json'; request.send(); return request.response; } var res_1 = asyncfunc1(); /* i dont to wait here, just let it work in the background */ res_2 = do some stuff.... res_3 = do more stuff total_res= res_1 + res_2 + res_3; /* how to wait for res_1 here */