Substituted allylic alcohols (2-buten-1-ol, 1-buten-3-ol, cinnamyl alcohol and 3-methyl-2-buten-1-ol) react with acyl isothiocyanates (4-chlorobenzoyl, 2,6-difluorobenzoyl, 3-phenylpropenoyl, 2-thienocarbonyl, 3-chloro-2-thienocarbonyl and 3-chloro-2-benzo[b]thienocarbonyl isothiocyanate) with the formation of highly reactive O-substituted allyl N-acylmonothiocarbamates, which either spontaneously or by heating in boiling benzene undergo [3,3]-sigmatropic rearrangement to S-substituted allyl N-acylmonothiocarbamates. The structure of S-esters with isomerized allylic group affords the unequivocal evidence of the [3,3]-sigmatropic route of studied rearrangement. Further heating of [3,3]-rearranged N-(4-chlorobenzoyl)monothiocarbamates results in the [1,3]-sigmatropic shift of monothiocarbamate group. Using arylalkyl alcohols with the allylic double bond inserted into an aromatic system the obtained O-esters either do not undergo any rearrangement (benzyl alcohol) or undergo [1,3]-sigmatropic rearrangement (2- and 3-furylmethanol and 1-(2-furyl)ethanol) to the corresponding S-esters. For explanation of this reaction the tandem of [3,3]- and [1,3]-sigmatropic rearrangements is suggested.
取代的
烯丙醇(
2-丁烯-1-醇,1-
丁烯-3-醇,
肉桂醇和3-甲基-
2-丁烯-1-醇)与酰基异
硫氰酸酯(4-
氯苯甲酰,2,6-二
氟苯甲酰,3-苯基
丙烯酰,2-
噻吩羰基,3-
氯-2-
噻吩羰基和3-
氯-2-苯[
b]
噻吩羰基异
硫氰酸酯)反应,形成高度活性的
O-取代的烯丙基
N-酰基单
硫代
氨基甲酸酯,这些产物会自发地或通过在沸腾的苯中加热而发生[3,3]-sigma转位重排,形成S-取代的烯丙基
N-酰基单
硫代
氨基甲酸酯。异构化烯丙基基团的
S-酯结构提供了研究重排的[3,3]-sigma路径的确凿证据。进一步加热[3,3]-重排的
N-(4-
氯苯甲酰)单
硫代
氨基甲酸酯会导致单
硫代
氨基甲酸酯基团的[1,3]-sigma转位。使用含有插入芳香环的烯丙双键的芳基烷基醇,所得的
O-酯要么不发生任何重排(
苄醇),要么发生[1,3]-sigma重排(2-和
3-呋喃甲醇和1-(2-
呋喃基)
乙醇)形成相应的
S-酯。为了解释这种反应,提出了[3,3]-和[1,3]-sigma转位重排的串联反应。