Not exactly...virtual memory is a technique to address larger ranges of memory than you actually have, usually swapping inactive programs to the hard disk.
Extended memory is all the memory above the first 640K of "conventional" memory + 384K of "expanded" memory. This extended memory is not accessible under normal operation in the old 8088 architecture (that's computer engineering shortsightedness for you); with the advent of x86 architecture, the CPU's protected mode allows this memory to be addressed.