Composition, synthesis, and use of new substituted pyran and pterin compounds

A method for preparing a compound of structure I:

• wherein X is selected from the group consisting of oxygen and sulfur and, R1 and R2 are each independently unsubstituted C1-C6 alkyl,
• comprising:
• a. obtaining an acetylene compound of structure II:
• wherein R1 and R2 are defined as above for structure I;
• b. combining the compound of structure II with a hydroxyl protecting group which forms a compound of structure III:
• wherein R1 and R2 are defined as above for structure I, and Y is a hydroxyl protecting group;
• c. deprotonating the compound of structure III and condensing the compound of the structure III with ethyl 2,2-diethoxy acetate ester which forms a substituted acetylene compound of structure IV:
• wherein R1 and R2 are defined as above for structure I, Et is ethyl, and Y is as defined above for structure III
• d. combining the substituted acetylene compound of structure IV with sulfurating agent 4-phenyl-1,3-dithiolane-2-thione to form a dithiolene substituted compound of structure V:
• wherein R1 and R2 are defined as above for structure I, and Et is as defined above for structure IV;
• and
• e. deprotecting acetal in the compound of structure V to form the compound of structure I.