14698-76-1Relevant articles and documents
Efficient entry into medium-ring keto-lactones. The ruthenium tetraoxide-promoted oxidative cleavage of β-hydroxyethers
Ferraz, Helena M. C.,Longo Jr., Luiz S.
, p. 1337 - 1339 (2003)
(Matrix presented) A new use of ruthenium tetraoxide is reported. The catalytic oxidative cleavage of hexahydro-benzofuran-3a-ols led to nine-membered ring keto-lactones in moderate to good yields and high purity. The reaction is clean and easily performed using catalytic amounts of ruthenium trichloride and an excess of sodium periodate as a cooxidant.
Total synthesis of (±)-chondrillin, (±)-plakorin, and related peroxy ketals. development of a general route to 3,6-dihydro-1,2-dioxin-3-ols
Snider, Barry B.,Shi, Zhongping
, p. 1790 - 1800 (2007/10/02)
Seven-step syntheses of the antitumor cyclic peroxy ketals la, 2a, chondrillin (Ib), and plakorin (2b) from (methoxymethoxy)benzene (8) have been achieved in 26-28% overall yields. The key step is the photooxygenation of enone 4 with a sun lamp using rose bengal lactone or CuSO4 as a sensitizer which gives a mixture of peroxy hemiketals 15 and 16 in 75-85% yields. Acetal formation in acidic methanol completes the syntheses of 1 and 2. The mechanism of photooxygenation was ascertained using 3-nonen-2-one (22) as a model for 4. Irradiation converts 22 to the cis-enone 23 which undergoes photoenolization to give 24. Dienol 24 undergoes a sensitized reaction with oxygen to give 29 and 30. The detailed mechanism of this last step is not known, although singlet oxygen is probably not involved. This reaction is general for any enone or enal which can undergo photoenolization to give a dienol. Peroxy hemiketals 33a, 41, and 43-46 were prepared in 30-80% yields. Peroxy ketals can be used for the synthesis of furans, diones, and pyridazines.
