在ajax中并行进行异步和同步调用

I am abit confused with idea of asynchronous and synchronous ajax calls.Is it possible to make one ajax call asynchrononously followed with a synchronous call??

Here's my scenerio, I am trying to make a real time progress bar to show no of data inserted where postdata() inserts data into table while getprocess() function returns the current no of data inserted to show in a progress bar.

Reference:: making progress bar

function getprogress(data){
      console.log(data);
                    $.ajax({
                             method: 'POST',
                              url: '<?php echo base_url()?>setting/processoffline/getprogressdata',
                              data:{ table:data },
                              dataType: 'json',
                              async: false,
                              success: function(val) {

                              var  off=parseFloat(Number(val.dataoffline),10);
                              var  on=parseFloat(Number(val.dataonline),10);
                              var    percent=Math.round((off/on)*100);

                            // $('#'+data+'success').addClass('hidden');
                               console.log('offline- '+off);
                               console.log('online- '+on);
                              $('#'+data+'progressbar').css('width',percent+"%");
                              $('#'+data+'progressbar').html(percent+"%" + off+' out of '+on );
                              if(percent=='100'){
                              console.log(percent);
                                // $('#'+data+'progressbox').addClass('hidden');
                                $('#'+data+'success').removeClass('hidden');
                                 $('.download').removeAttr('disabled','disabled');
                                 // clearTimeout();
                              }
                              console.log(postComplete);
                              if (!postComplete)
                                      setTimeout( function() { getprogress(data); }, 1500);
                                } ,
                              error: function() { 
                                if (!postComplete){
                                     setTimeout( function() { getprogress(data); }, 1500);
                               }
                              }

                          });
    }
    function postdata(data)
    {
      // if(!data)


             $.ajax({
                              method: 'POST',
                              url: '<?php echo base_url()?>setting/processoffline/processdata',
                              data:{ master_table:data },
                              dataType: 'html',
                              success: function() {
                                postComplete = true;

                               },
                              error: function() { 
                                postComplete = true;
                              }

                          });
    }

Now here's how I call these functions for use

 $(this).parent('td').parent('tr').siblings('tr').children('td').find('input:checked').each(function(){

              data=$(this).attr('id');
              postdata(data);
              $('#'+data+'success').addClass('hidden');
              $('#'+data+'progressbox').removeClass('hidden');


               i++;

                  getprogress(data);
             if(!postComplete)
             setTimeout( function() { getprogress(data);}, 2);

Here postdata() function is called multiple times in loop asynchronously my case is that since loop can be for unlimited number, that can start lot of parallel processes that can hang up my system so .I need to start next loop for postdata() only when the earlier process is over.Function postdata() makes ajax call for php function that requires a lot of time.So my technique is to define postdata() function asynchronously so that I can call getprogress() function parallely but (don't know if possible) I want to call getprocess ajax call synchronously so that loop will wait until value returned from getprogress is over.In this way I can start a new process in ajax call only when earlier process is over.

I want to know if it is possible or not and if not how can i manage this issue.Sorry for bad english and If unclear please comment and I am stuck to this for 3-4 days. Thanks in advance