2028-52-6Relevant articles and documents
Synthesis of α-Acyloxy-α′-hydroxy Ketones via Cyclic Carbonate Intermediates Generated from Tertiary Bromopropargylic Alcohols and Cs2CO3
Shemyakina, Olesya A.,Volostnykh, Ol'ga G.,Stepanov, Anton V.,Ushakov, Igor' A.
supporting information, p. 7117 - 7121 (2019/11/16)
A facile approach towards α-acyloxy-α′-hydroxy ketones by reaction of readily available tertiary bromopropargylic alcohols and carboxylic acids in system Cs2CO3/H2O/DMF (50–55 °C, 4 h) was developed. Key intermediates of this synthesis are cyclic carbonates generated in situ from bromopropargylic alcohols and Cs2CO3 which have been utilized as both reagent and base promoter.
Chemo-and regiospecific modification of D,L-tryptophan by reaction with α,β-acetylenic γ-hydroxy nitriles
Trofimov, Boris A.,Malkina, Anastasiya G.,Borisova, Angela P.,Shemyakina, Olesya A.,Nosyreva, Valentina V.,Albanov, Alexander I.
scheme or table, p. 3174 - 3178 (2010/10/21)
D,L-Tryptophan reacts with α,β-acetylenic γ-hydroxy nitriles, chemo-and regiospecifically, under mild, green conditions via a hydroamination-type process involving the primary amine group. The hydroxycyanopropanyl substituent of the initial adducts underg
1-Halo-1-acceptor-/1,1-diacceptor-substituted allenes, 9: Functionalized allenes, haloallenes, and bisallenes via [2,3]/[3,3]-sigmatropic rearrangements and their reactivity
Saalfrank, Rolf W.,Welch, Andreas,Haubner, Martin,Bauer, Udo
, p. 171 - 181 (2007/10/03)
Reaction of carbonyl compounds 1 with trimethylsilylacetylene 2 leads to the alkynols 3, which are excellent precursors of acceptor-substituted allenes. Compound 3 reacts with carbamoyl chloride 4, diethyl chlorophosphate 6, or hypohalite 8 to give the substituted alkynols 5, 7, 9. Reaction of 9 with sulfinyl chloride 10 leads to the sulfinic esters 11, which on heating undergo a [2,3]-sigmatropic shift to yield the halosulfonyl allenes 12. In the same manner the reaction of 7 and 9 with chlorophosphanes 13 or sulfenyl chlorides 15 gives rise to the generation of the phosphoryl allenes 14 and the haloallenyl sulfoxides 16, respectively. Alkynyl ketene acetal intermediates 18 are formed by starting from the alkynols 9 and orthoesters 17. Spontaneous [3,3]-sigmatropic rearrangement of 18 gives the haloallenyl esters 19. Reaction of alkynols 5 with sulfur dichloride leads to the alkynylsulfinyl esters 20, which on heating rearrange to the bisallenyl sulfones 21. Pyrolysis of 21 yields the thiophene 1,1-dioxides 22. Bisphosphorylbisallene 24 is synthesized from hexadiyndiol 23 by reaction with chlorodiethoxyphosphite. Halophosphoryl allenes 14 react with bromine to yield the oxaphospholenes 25 by cyclization and subsequent elimination of ethanol, or oxaphospholenes 26, if no appropriate leaving group is present in the molecule. Sulfonyl-1,3-dienes 27 can be synthesized by reaction of halosulfonylallenes 12 with bromine, followed by elimination of HBr. Haloallenyl ester 19a is converted in a non-generalizable reaction with bromine into the tribromo3,6-dihydro-2-pyranone 30. VCH Verlagsgesellschaft mbH, 1996.
