Synlett 2002(8): 1341-1343
DOI: 10.1055/s-2002-32985
LETTER
© Georg Thieme Verlag Stuttgart · New York

Syntheses of Gabosine A, B, D, and E from Allyl Sulfide Derived from(-)-Quinic Acid

Tetsuro Shinada*, Toshiyuki Fuji, Yasuhiro Ohtani, Yasutaka Yoshida, Yasufumi Ohfune*
Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi, Osaka 558-8585, Japan
Fax: +81(6)66053153; e-Mail: shinada@sci.osaka-cu.ac.jp; e-Mail: ohfune@sci.osaka-cu.ac.jp;
Further Information

Publication History

Received 15 May 2002
Publication Date:
25 July 2002 (online)

Abstract

An efficient conversion of allyl sulfide 6 prepared from (-)-quinic acid (5) to gabosines was achieved by a series of sequential reactions: i) Mislow-Evans rearrangement, ii) SeO2 oxidation, iii) conjugate addition of sodium hydroxide or sodium acetate, and iv) elimination of the methoxymethyloxy group.

6

The exclusive diastereofacial rearrangement would be induced by the steric repulsion of the bulky allylic silyloxy group which lies on the α-face of the cyclohexane ring.

7

Structures of 9, 11a, and 11b were confirmed by their conversions into conduritols A and C. Full details of these results will be reported in due course.

10

Yields on the deprotection step to gabosines were good to moderate (>59%) due probably to the prolonged reaction period leading to the undesired acid-catalyzed decomposition.