87797-68-0Relevant academic research and scientific papers
Towards the Sarpagine-Ajmaline-Macroline Family of Indole Alkaloids: Enantioselective Synthesis of an N-Demethyl Alstolactone Diastereomer
Dagoneau, Dylan,Wang, Qian,Zhu, Jieping
, p. 4866 - 4873 (2020)
the strategy involving the use of functionalized tetrahydro-6H-cycloocta[b]indol-6-one is reported as a key intermediate for synthesis of members of the sarpagine-ajmaline-macroline family of monoterpene indole alkaloids. The desired tricycle was synthesized through the following key steps: 1) Evans’ syn-selective aldolization; 2) Liebeskind–Srogl cross-coupling using the phenylthiol ester of 3-chloropropanoic acid as a surrogate of acrylic thioester for the synthesis of 2,3-disubstituted indoles; and 3) ring-closing metathesis (RCM) for the formation of the eight-membered ring. An N-allylation followed by intramolecular 1,4-addition was planned for synthesis of the vobasine class of natural products. However, attempted cyclizations under a diverse set of conditions involving anionic, radical, and organopalladium/organonickel species failed to produce the bridged ring system. On the other hand, esterification of the pendant primary alcohol function with acetoacetic acid, followed by intramolecular Michael addition, afforded the desired tetracycle with excellent diastereoselectivity. Subsequent functional group manipulation and transannular cyclization of the amino alcohol afforded the N(1)-demethyl-3,5-diepi-alstolactone. We believe that the same synthetic route would afford the alstolactone should the amino alcohol with appropriate stereochemistry be used as the starting material.
Method for Producing Carboxylic Acid Thioester
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Paragraph 0077-0083, (2018/11/02)
According to the present invention, there is provided a method for producing carboxylic acid thioester, comprising reacting a compound represented by the following formula (I), carboxylic acid and thiol in the presence of a catalyst including at least one Group 2 metal compound. The production method is a production method which is simple in reaction operation, which places a small load on the environment and the human body and which enables carboxylic acid thioester to be catalytically obtained at a high yield even at a normal temperature and a normal pressure (25° C., 1 atm). In the formula (I), R1 and R2 each independently represent a hydrocarbon group having 1 to 20 carbon atoms.
Novel Alumina-catalysed Reactions of Arylthioalkyl Halides and Related Compounds
Jigajinni, Veerappa B.,Wightman, Richard H.
, p. 1801 - 1812 (2007/10/02)
Arylthioalkyl halides of the type ArS(CH2)nCl (Ar = phenyl or substituted phenyl, n = 1-4) undergo rearrangement on heating with neutral alumina to 1,n-bis(arylthio)alkanes of type ArS(CH2)nSAr in high yield.Similar rearrangements occur with some closely related structural types.The bis(arylthio)alkanes undergo further reaction with alumina at higher temperatures in air giving diaryl disulphides.Bis(o-iodophenylthio)methane eliminates iodine on heating with alumina, producing dibenzodithiepin.Some observations concerning the mechanism are presented.
