Meyer-Schuster Rearrangement of .gamma.-Sulfur-Substituted Propargyl Alcohols: A Convenient Synthesis of .alpha.,.beta.-Unsaturated Thioesters
摘要:
gamma-Sulfur-substituted propargyl alcohols 1a-e and 1ij reacted with polyphosphoric acid trimethylsilyl ester (PPSE) to give the alpha,beta-unsaturated thioesters 3a-e and 3ij in good yields. However, the reactions of 3,3-dibutyl-1 -(phenylthio)propargyl alcohol (1k) and 1-(phenylthio)ethynyl- 1-cyclo alkanols 1l-n with PPSE gave the enyne sulfides 2k-n exclusively.
Electroinitiated oxygenation of alkenyl sulfides and alkynes in the presence of thiophenol
作者:Junichi Yoshida、Shogo Nakatani、Sachihiko Isoe
DOI:10.1021/jo00070a021
日期:1993.8
Electrolysis of alkenyl sulfides in the presence of thiophenol with bubbling of molecular oxygen gave the corresponding alpha-(phenylthio) carbonyl compounds with the consumption of a catalytic amount of electricity. An electroinitiated radical chain mechanism has been proposed. The reaction also took place without electrochemical initiation, but much (5-50 times) longer reaction time was required for the completion of the reaction. The potential utility of the present reaction in organic synthesis is demonstrated by the net 1,2-transposition of a phenylthio group and a carbonyl group. The electroinitiated oxygenation of ketene dithioacetals also proceeded smoothly to give the corresponding alpha-(phenylthio) thiol esters. It was also found that the electroinitiated oxygenation of alkynes in the presence of thiophenol gave alpha-(phenylthio) carbonyl compounds. A mechanism involving the initial formation of alkenyl sulfides has been proposed.