Synthesis of 1,2,4-trioxepanes and 1,2,4-trioxocanes via photooxygenation of homoallylic alcohols.
Homoallylic alcohols 4a-d, easily accessible in two steps from cyclopropyl methyl ketone, underwent a highly regioselective reaction with singlet oxygen to yield gamma-hydroxyhydroperoxides 5a-d in 57-72% yield. Acid-catalyzed reaction of 5a-d with acetone, cyclopentanone, and cyclohexanone furnished 1,2,4-trioxepanes 8a-d, 9a-d, and 10a-d in good yields. Homoallylic alcohol 12 also underwent a highly regioselective photooxygenation to yield gamma-hydroxyhydroperoxide 13 in 67% yield, which on reaction with acetone, cyclopentanone, and cyclohexanone, furnished 1,2,4-trioxocanes 16-18 in 41-55% yield.
Singh
Chandan
C
Division of Medicinal and Process Chemistry, Central Drug Research Institute, Lucknow-226001, India. chandancdri@yahoo.com
Pandey
Shilpi
S
Saxena
Gunjan
G
Srivastava
Nisha
N
Sharma
Malvika
M
D002384:Catalysis; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010777:Photochemistry; D020005:Propanols / Q000737:chemistry*; D026082:Singlet Oxygen / Q000737:chemistry*
D020005:Propanols; D026082:Singlet Oxygen; C006463:allyl alcohol