A thiol-containing ester side chain in a sesquiterpene lactone from Eupatorium mikanioides. Absolute configuration of deacetyleupaserrin and its congeners

Derivatives of 21-nor-5α-cholane-20,24-diol XI and XIX were prepared by stepwise construction of the side-chain in the position 17β. Their absolute configuration at C(20) was determined on the basis of chemical correlation with the derivatives of 21-nor-5α-cholan-20-ol, XVI and XXIV. The absolute configuration of alcohols XVI and XXIV was determined from the ratio of the yields in which they are formed during the reduction of ketone X and using the benzoate rule. To compounds XI-XVIII the configuration 20R and to compounds XIX-XXVI the configuration 20S has been assigned.

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(3aS,5aR,6R,8aR)-3a-Hydroxy-5a-methyl-6-[(1R,2E,4R)-1,4,5-trimethyl-2-hexen-1-yl]-3a,4,5,5a,6,7,8,8a-octahydro-2H-cyclopenta[e]benzofuran-2-one

Acta Crystallographica Section E Structure Reports Online ◽

10.1107/s1600536807047307 ◽

2007 ◽

Vol 63 (11) ◽

pp. o4196-o4196

Author(s):

Wen-liang Wang ◽

Hong-wen Tao ◽

Wei Sun ◽

Qian-Qun Gu ◽

Wei-Ming Zhu

Keyword(s):

Crystal Structure ◽

Hydrogen Bonds ◽

Absolute Configuration ◽

Title Compound ◽

Optical Rotation ◽

Side Chain ◽

Compound C ◽

Extended Chain ◽

Halotolerant Fungus ◽

The Absolute

The title compound, C21H32O3, also known as dimethylincisterol A3, was isolated from halotolerant fungus THW-18. It is composed of three fused rings and a side chain. In the crystal structure, the molecules interact with each other via O—H...O hydrogen bonds, resulting in an extended chain along the b axis. The absolute configuration was assigned from the measured optical rotation and reference to the literature.

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The absolute configuration of the side chain diol moiety of the poison-frog alkaloid pumiliotoxin B

Toxicon ◽

10.1016/0041-0101(84)90123-5 ◽

1984 ◽

Vol 22 (3) ◽

pp. 489-490

Author(s):

H.P. Kolm

Keyword(s):

Absolute Configuration ◽

Side Chain ◽

Poison Frog ◽

The Absolute

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Bacterial sterol surrogates. Determination of the absolute configuration of bacteriohopanetetrol side chain by hemisynthesis of its diastereoisomers

The Journal of Organic Chemistry ◽

10.1021/jo00273a034 ◽

1989 ◽

Vol 54 (12) ◽

pp. 2958-2964 ◽

Cited By ~ 34

Author(s):

Philippe Bisseret ◽

Michel Rohmer

Keyword(s):

Absolute Configuration ◽

Side Chain ◽

The Absolute

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X-ray crystal structure analysis of a bisepoxide derived from secologanin: the structure and absolute configuration

Canadian Journal of Chemistry ◽

10.1139/v83-050 ◽

1983 ◽

Vol 61 (2) ◽

pp. 282-283 ◽

Cited By ~ 8

Author(s):

Stanley C. Nyburg ◽

Pik Y. Siew ◽

Gavin N. Saunders ◽

John R. Purdy ◽

Stewart McLean

Keyword(s):

Crystal Structure ◽

Structure Analysis ◽

Absolute Configuration ◽

Dimethyl Acetal ◽

Crystal Structure Analysis ◽

Side Chain ◽

Bench Mark ◽

Chemical Transformations ◽

X Ray ◽

Derivatives Of

The structure and absolute configuration of a bisepoxide (2) produced by oxidation of tetraacetylsecologanin dimethyl acetal (1) with m-chloroperbenzoic acid have been established by X-ray crystal structure analysis. Epoxidation of the vinyl side chain is unexceptional; epoxidation of the β-alkoxyacrylate moiety is novel. This determination represents a valuable bench mark for configurational assignments, since the bisepoxide has been correlated by chemical transformations with a number of synthetic and naturally-occurring derivatives of secologanin.

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