Can be done IF you are using light tubing and not too big. Yes, the "flexy" light stuff.
Columbus KL or Reynolds 3/10 ga. 531. A smaller early Masi 3V could do it too.
Tubulars, 28 or 28/32 hole wheels, and weight weenie compromises.

Frame tubing and frame size is your biggest mass budget consumer.

Don't be afraid of the French either.
Huret Jubilee, TA cranks… Mafac plastic body levers, Weinmann 500 brakes or Aero Gran Compe calipers if you are in the 80's era. It all adds up. 250 gram tires..
forget traditional leather saddles…
a few guys got between 18-19 lbs but nothing bigger than 56 cm center to top.