dispatch_async内でUIViewが更新されない

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0),
非同期 .. 処理は止まらないがdispatch内処理後数十秒経ってからUIViewが更新される
dispatch_sync(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0),
同期 .. dispatch内処理中はフリーズしてしまう

UIView更新の時だけdispatch_sync dispatch_get_main_queue使う

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
                NSError* error = nil;
                NSString* url=[NSStringstringWithFormat:@"http://"];
                NSURLRequest* request = [NSURLRequestrequestWithURL:[NSURLURLWithString:url] cachePolicy:NSURLRequestReloadIgnoringCacheDatatimeoutInterval:5.0];
                NSData* data = [NSURLConnectionsendSynchronousRequest:request returningResponse:nilerror:&error];
                if (!i) {
                    dispatch_sync(dispatch_get_main_queue(), ^{ // mainキューでしかUIViewは更新されないので、更新される瞬間だけmainキューで処理
                        imagee[i].image = [UIImageimageWithData:data];
                        [self.draggableViewaddSubview:imagee[0]];
                        [self.draggableViewreloado];
                    });
                } else
                   
                    if (i==1) {
                        dispatch_sync(dispatch_get_main_queue(), ^{
                            imagee[i].image = [UIImageimageWithData:data];
                            [self.hakooaddSubview:imagee[1]];
                        });
                    } else {
                        imagee[i].image = [UIImageimageWithData:data];
                    }           
        });