Synthesis 1994; 1994(6): 567-572
DOI: 10.1055/s-1994-25525
paper
© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

(Z)-3-Alkylidene-4,5-dihydro-4-hydroxy-5-methyl-2-(3H)-furanones by Regio- and Diastereo-selective Ene Reaction of Singlet Oxygen (Schenk Reaktion) with γ-Hydroxy Vinylstannanes: An Enantioselective Synthesis of Dihydromahubanolide B

Waldemar Adam* , Peter Klug
  • *Institute of Organic Chemistry, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
Further Information

Publication History

Publication Date:
17 September 2002 (online)

(Z)-3-Alkylidene-4,5-dihydro-4-hydroxy-5-methyl-2-(3H)-furanones 5 were prepared from appropriately substituted propargylic alcohols 1 by a sequence of hydromagnesation to γ-hydroxy vinylstannanes 2, subsequent photooxygenation and reduction to stannyl diols 3, iododestannylation to iodo diols 4, and finally cyclization by palladium-catalyzed carbonylation (for 5a) or Ni(CO)2(PPh3)2 (for 5b,c). The reaction sequence can be performed enantioselectively by starting with chiral propargylic alcohols. The current approach constitutes a convenient four-step synthesis of optically active lactones 5 from readily available starting materials and is applied herein to the preparation of the natural lactone dihydromahubanolide B.