Regio- and Stereoselective Reactions of (S)-(1-Methylpyrrolidin-2-yl)methyl Allyl Sulfide

  • Park, Ho-Koon (Natural Product Chemistry Laboratory, Korea Institute of Science and Technology) ;
  • Baik, Nam-Hoon (Department of Chemistry, Kyung-Hee University) ;
  • Lee, Jae-Yeol (Department of Chemistry, Kyung-Hee University) ;
  • Kim, Soo-Ja (Department of Chemistry, Kyung-Hee University) ;
  • Ham, Won-Hoon (College of Pharmacy, Sung-Kyun-Kwan University)
  • Published : 1991.12.01

Abstract

The synthesis and regioselective reactions of a chiral allyl sulfide. (S)-(+)-(1-methylpyrrolidin-2-yl)methyl allyl sulfide (MAS, 1) are described. Remarkable ${\alpha}-regioselectivity$ was observed in the alkylation of the carbanion of MAS while 1:3 mixtures of ${\alpha}-and\;{\gamma}-adducts$ were produced in the addition of the MAS anion to aldehydes. However, a dramatic change of the regioselectivity was witnessed when Lewis acids such as $Et_3Al$, $Et_3B$, and $Ti(O^iPr)_4$ were used as additives in the addition reaction. In these cases, ${\alpha}-adducts$ were formed exclusively. A rationale for the change of regioselectivity is provided. And the stereochemical aspect of the addition reaction is also described.

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