Thiamine 1 is an essential component of the human diet; in is absence, the human vitamin deficiency known as beriberi develops.

i. List the requirements for aromaticity. 

ii. Show that each ring of thiamine 1 fulfills the requirements for aromaticity. 

iii. If the acetamide (H2N-CNH-CH3), in Step 1 was replaced by urea (H2N-CO-NH2), what would the product of Step 1 be? 

c NH2 CH3 H3C CH2CH2OH 1