(R)-(+)- and (S)-(-)-5-Ethyl-5-methyl-1,3-dioxolane-2,4-dione reagents for the direct preparation of .alpha.-hydroxy-.alpha.-methylbutyrate esters: assignment of the absolute configuration of the .alpha.-acetoxy-.alpha.-methylbutyrate ester side chain of quassimarin via total synthesis

1993 ◽  
Vol 58 (15) ◽  
pp. 3789-3790 ◽  
Author(s):  
Eric D. Moher ◽  
Paul A. Grieco ◽  
Jon L. Collins
Keyword(s):  
Total Synthesis ◽  
Absolute Configuration ◽  
Side Chain ◽  
Direct Preparation ◽  
The Absolute

Absolute configuration at C(20) of the derivatives of 21-nor-5α-cholane-20,24-diol

1980 ◽  
Vol 45 (9) ◽  
pp. 2443-2451
Author(s):  
Vladimír Pouzar ◽  
Miroslav Havel
Keyword(s):  
Absolute Configuration ◽  
Side Chain ◽  
Chemical Correlation ◽  
The Absolute ◽  
Derivatives Of

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.

Asymmetric Total Synthesis and Determination of the Absolute Configuration of (+)-Srilankenyne via Sequence-Sensitive Halogenations Guided by Conformational Analysis

2021 ◽  
Vol 23 (4) ◽  
pp. 1321-1326
Author(s):  
Hongjun Jang ◽  
Soo Yeon Kwak ◽  
Dongjoo Lee ◽  
Juan V. Alegre-Requena ◽  
Hyoungsu Kim ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Conformational Analysis ◽  
Absolute Configuration ◽  
Asymmetric Total Synthesis ◽  
The Absolute

Total synthesis and determination of the absolute configuration of (−)-longilene peroxide

2001 ◽  
Vol 42 (36) ◽  
pp. 6307-6309 ◽  
Author(s):  
Yoshiki Morimoto ◽  
Toshiyuki Iwai ◽  
Takamasa Kinoshita
Keyword(s):  
Total Synthesis ◽  
Absolute Configuration ◽  
The Absolute

(-)-Strempeliopine, stereoselective total synthesis and the determination of absolute configuration

1986 ◽  
Vol 51 (8) ◽  
pp. 1731-1742 ◽  
Author(s):  
Josef Hájíček ◽  
Jan Trojánek
Keyword(s):  
Circular Dichroism ◽  
Total Synthesis ◽  
Absolute Configuration ◽  
Determination Of Absolute Configuration ◽  
Natural Base ◽  
The Absolute ◽  
Circular Dichroïsm

A synthesis of (±)-strempeliopine (II) is described, the key step of which is the stereoselective reductive rearrangement of 18-methylene-1,2-dehydroaspidospermidine (XI). The absolute configuration of the natural (-)-base II was determined as (2S, 7R, 20R, 21R) on the basis of its synthesis from (+)-18-methylenevincadifformine (XVII) the configuration of which was derived from a comparison of circular dichroism properties of bases with a β-anilinoacrylate chromophore. The biogenesis of the alkaloids of the schizozygane type is discussed.

First Total Synthesis and Determination of the Absolute Configuration of Strictifolione, a New 6-(ω-Phenylalkenyl)-5,6-dihydro-α-pyrone, Isolated from Cryptocarya strictifolia.

ChemInform ◽  
2003 ◽  
Vol 34 (7) ◽  
Author(s):  
Lia Dewi Juliawaty ◽  
Yoshimi Watanabe ◽  
Mariko Kitajima ◽  
Sjamsul Arifin Achmad ◽  
Hiromitsu Takayama ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Absolute Configuration ◽  
The Absolute
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