An appropriately substituted 1-alkenyl-4-pentyn-1-ol system, readily prepared from simple starting materials, undegoes a microwave-assisted tandem cyclization/Claisen rearrangement sequence to generate the necessary cyclohept-4-enone precursor in the total synthesis of (±)-frondosin A.  Frondosin A has been extracted from the sea sponge Dysidea frondosa and exhibits anti-HIV and anti-tumor activities.