| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1344922 | Tetrahedron: Asymmetry | 2008 | 7 Pages |
Versatile optically active 6,7-monoepoxyzerumbones (+)-8 and (−)-8 were obtained by oxidation of the corresponding monoepoxyzerumbols. Optically active erythro monoepoxyzerumbol (1R)-9 and its acetate (1S)-12, and threo (1R)-10 and its acetate (1S)-11 were synthesized by lipase-catalyzed enantioselective transesterification of racemic compounds 9 and 10. The absolute configuration of (1R)-10 was determined by X-ray analysis after conversion to its ester with chlorine and that of (1R)-9 was determined by conversion to the corresponding 6,7-monoepoxyzerumbone. Interestingly, the stereoselectivity of 6,7-monoepoxyzerumbol obtained by lipase-catalyzed transesterification contrasted with that of the 2,3,6,7,10,11-triepoxides.
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(6R,7R)-6,7-Epoxy-2,6,9,9-tetramethyl-2,10-cycloundecadien-1-oneC15H22O2Ee = 92%[α]D23.5=+7.8 (c 1.00, CHCl3)Source of chirality: lipase resolutionAbsolute configuration: (6R,7R)
(6S,7S)-6,7-Epoxy-2,6,9,9-tetramethyl-2,10-cycloundecadien-1-oneC15H22O2Ee = 99.5%[α]D23.5=-9.7 (c 1.00, CHCl3)Source of chirality: lipase resolutionAbsolute configuration: (6S,7S)
(1R,6R,7R)-6,7-Epoxy-2,6,9,9-tetramethyl-2,10-cycloundecadien-1-olC15H24O2Ee = 92%[α]D23.5=-43.1 (c 1.01, CHCl3)Source of chirality: lipase resolutionAbsolute configuration: (1R,6R,7R)
(1R,6S,7S)-6,7-Epoxy-2,6,9,9-tetramethyl-2,10-cycloundecadien-1-olC15H24O2Ee = 99.6%[α]D23.5=+82.4 (c 1.01, CHCl3)Source of chirality: lipase resolutionAbsolute configuration: (1R,6S,7S)
(1S,6R,7R)-1-Acetoxy-6,7-epoxy-2,6,9,9-tetramethyl-2,10-cycloundecadieneC17H26O3Ee = 34%[α]D23.5=-31.4 (c 1.02, CHCl3)Source of chirality: lipase resolutionAbsolute configuration: (1S,6R,7R)
(1S,6S,7S)-1-Acetoxy-6,7-epoxy-2,6,9,9-tetramethyl-2,10-cycloundecadieneC17H26O3Ee = 87%[α]D23.5=+5.1 (c 1.01, CHCl3)Source of chirality: lipase resolutionAbsolute configuration: (1S,6S,7S)
