Spiro siklopentenon-piran ve spiro dihidropiran bileşiklerinin sentezi

Spiro cyclic compounds found in the structure of natural product that has biological activities. The structures contain cyclopentenone pyran ring composed of cylopentenone ring known as cyclopentenone prostaglandins which are used in the treatment of psychological diseases. Dihydropyran ring contain compounds found in the structure of molecules used in the anti-cancer treatment drugs. Pauson-Khand reaction and Ring Closing Metathesis are frequently used methods in the literature for synthesize of spirocyclic units. In this study, 6-oxaspiro[4.5]deca-1,8-diene 66 and 1-oxaspiro[5.5]undeca-3,7-diene 72 was obtained by Ring Closing Metathesis using Grubbs First Generation Catalyst with 80 % and 82 % overall chemical yield respectively. Then, 4a?,5?-dihydro-1'H-spiro[cyclopent[2]ene-1,3'-cyclopenta[c]pyran] -6'(4'H)-one 68 was synthesized via Pauson-Khand Reaction in the presence of NMO as a promoter and Co(CO)8 with 82 % overall chemical yield. In the same manner 4a',5'-dihydro-1'H-spiro[cyclohex[2]ene-1,3'-cyclopenta[c]pyran]-6'(4'H)-one 74 was obtained with % 84 overall chemical yield.