5953-76-4Relevant articles and documents
A METHOD OF PRODUCING INGENOL-3-ANGELATE
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Page/Page column 55-56, (2012/02/05)
The present invention relates to methods of producing ingenol-3-angelate (I) from ingenol (II). Formula (I) and (II). Furthermore, the invention relates to intermediates useful for the synthesis of ingenol-3-angelate (I) from ingenol (II) and to methods of producing said intermediates.
A new 1,5- to 1,11-carbonyl transposition protocol involving ketene dithioacetal chemistry: An efficient polyene synthesis
Asokan,Shukla,Kumar,Ila,Junjappa
, p. 937 - 947 (2007/10/03)
An efficient strategy for alternative 1,5-, 1,7-, 1,9- and 1,11- carbonyl transposition has been developed via 1,2-reductive or alkylative addition to 5,5-bis(methylthio)-2,4-pentadienals 3a-b, 7,7-bis(methylthio)-2,4,6-heptatrienones 5,9,9-bis(methylthio)-2,4,6,8-nonatetraenones 8 and 11,11-bis(methylthio)-2,4,6,8,10-undecapentaenones 11 followed by BF3,Et2O induced methanolysis of the resulting carbinols to the corresponding polyene esters. The synthesis of the novel polyene aldehydes 3a-b, 7a-b, 10b and polyenones 5, 8, 11 precursors has also been described following iterative Vielsmeier-Haack reaction and aldol condensation.
Regioselective Reaction of Singlet Oxygen with α,β-Unsaturated Esters
Orfanopoulos, Michael,Foote, Christopher S.
, p. 5991 - 5994 (2007/10/02)
The reaction of singlet oxygen with α,β-unsaturated esters shows a general preference for hydrogen abstraction on the alkyl group geminal to the ester.
Cyclopropanation of α,β-Unsaturated Carbonyl Compounds and Nitriles with Diazo Compounds. The nature of the Involvement of Transition-Metal Promoters
Doyle, Michael P.,Dorow, Roberta L.,Tamblyn, William H.
, p. 4059 - 4068 (2007/10/02)
In the presence of molybdenum hexacarbonyl or molybdenum(II) acetate, ethyl diazoacetate and α-diazoacetophenone react with α,β-unsaturated carbonyl compounds and nitriles to form derivative cyclopropane and vinyl CH insertion products.In the absence of these promoters or in the presence of catalytic amounts of pyridine, 2-pyrazolines are the major or sole reaction products.Kinetic investigations for reactions between ethyl diazoacetate and α,β-unsaturated esters and nitriles in the presence of Mo(CO)6, Mo2(OAc)4, or pyridine demonstrate the absence of any significant influence by these molybdenum promoters or pyridine on the rates and activation parameters for ethyl diazoacetate decomposition.Representative 1-pyrazolines have been synthesized and observed to undergo dinitrogen extrusion without apparent influence by molybdenum promoters.The composite results suggest that these molybdenum promoted reactions occur by dipolar cycloaddition of diazocarbonyl compounds to α,β-unsaturated systems and that the derivative 1-pyrazoline intermediates undergo dinitrogen extrusion to form the observed cyclopropane and vinyl CH insertion products.Molybdenum promoters function to inhibit competitive tautomerization of the initially formed cycloaddition products.The relative effectiveness of a broad selection of transition-metal compounds in directing reactions between ethyl diazoacetate and α,β-unsaturated esters and nitriles to cyclopropane products is described.The cycloaddition / dinitrogen extrusion pathway is presented as a viable mechanism for cyclopropanation of α,β-unsaturated systems by diazo compounds, even for reactions performed in the presence of traditional cyclopropanation catalysts.
