158388-75-1Relevant academic research and scientific papers
Cycloadditions, XXII Synthesis and Thermal Reaction of S-(Alkyl/Aryl)-2,3-butadienethioates
Himbert, Gerhard,Fink, Dieter
, p. 542 - 550 (2007/10/02)
While the S-alkyl- or S-phenyl-2,3-butadienethioates 4a-c are synthesized via the usual "Wittig ylide way", the corresponding 2-methyl-2,3-butadienethioates 9a-d and the 2-methyl-4,4-diphenyl-2,3-butadienethioates 9e,f are obtained by condensation of the allenic acids 7a,b with the thiols and thiophenols 8 in the presence of dicyclohexylcarbodiimide (DCC) and a catalytic amount of 4-dimethylaminopyridine (DMAP).In contrast to N- or O-phenyl 2,3-butadienamides or -esters, resp., the phenyl derivatives of 4 and 9 do not undergo the intramolecular Diels-Alder reaction, but by heating, all representatives of 4 only decompose, while 9a-d and 9e,f rearrange to 3-alkyl(aryl)thio-2-cyclobuten-1-ones 12a-d and to 3-arylthio-1-naphthols 14a,b, resp.Heating of the cyclobutenone 12d in the presence of N-methylaniline furnishes the 2-butenanilide 16.On reacting 1-phenylthio-1-propyne 17 with diphenylketene 18, the diphenylacetate 19 is isolated, where the naphthol derivative 14 a represents the ester moiety. - Keywords: S-(Alkyl/Aryl)-2,3-butadienethioates, 3-Alkyl(aryl)thio-2-cyclobuten-1-ones, 3-Arylthio-1-naphthols
