77269-22-8Relevant articles and documents
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.
ISOMERAZATION OF PROPARGYLIC ALCOHOLS CATALYZED BY AN IRIDIUM COMPLEX
Ma, Dawei,Lu, Xiyan
, p. 2109 - 2112 (2007/10/02)
α,β-Enones were synthesized by the isomerization of propargylic alcohols catalyzed by an iridium pentahydride complex.
ADDITION DE L'ACETONE A DES ALCYNES VRAIS FONCTIONNELS OU NON
Gardrat, C.,Montaudon, E.,Lalande, R.
, p. 1039 - 1042 (2007/10/02)
Acetonyl radicals created by action of di-t-butylperoxide on acetone (molar ratios acetone/acetylenic compound/DTBP = 20/1/0.2 ; 150 deg C ; 3h) add to acetylenic compounds and lead to the formation of 1/1 adducts in low to moderate yields. 2/1 adducts ar
