Preparation of (4R,5S)-(5-methyl-2,2-dimethyl-1,3-dioxolane-4-ylmethyl)-phosphonium iodide. A synthetic approach to olguine: further model studies

1987 ◽  
Vol 65 (2) ◽  
pp. 332-338 ◽  
Author(s):  
Serafin Valverde ◽  
Bernardo Herradon ◽  
Rosa M. Rabanal ◽  
Manuel Martin-Lomas

The enantiomerically pure title compound ((4R,5S)-(5-methyl-2,2-dimethyl-1,3-dioxolane-4-ylmethyl)-phosphonium iodide) has been synthesized starting from (R,R)-(+)-tartaric acid. The synthesis of an olguine analog has been carried out. Attempts have been made to improve the stereoselectivity and yield of key steps.

1987 ◽  
Vol 65 (9) ◽  
pp. 2316-2316 ◽  
Author(s):  
S. Valverde ◽  
B. Herradón ◽  
R. M. Rabanal ◽  
M. Martín-Lomas

not available


Synlett ◽  
2021 ◽  
Author(s):  
Jiangchun Zhong ◽  
Gucheng Yuan ◽  
Jiawei Liu ◽  
Shihang Yu ◽  
Xueyang Wang ◽  
...  

AbstractThe synthesis of a Miltochrista calamine sex pheromone and its diastereomer has been developed. The key steps of the synthetic approach involved Evans’ chiral auxiliaries and the addition of alkyne to aldehyde, which were firstly applied to prepare this sex pheromone and its diastereomer. The synthetic sex pheromone could be used to trap insects and study physiological and ecological questions of the lichen moth.


Synlett ◽  
2019 ◽  
Vol 30 (07) ◽  
pp. 860-862 ◽  
Author(s):  
Yun Zhou ◽  
Chunxiao Liu ◽  
Lifeng Wang ◽  
Leng Han ◽  
Shicong Hou ◽  
...  

A novel, concise, and efficient enantioselective synthesis of (S)-preclamol (87% ee, 51% total yield) has been developed. The key steps of this synthetic approach included cobalt-catalyzed asymmetric catalytic cross-coupling of α-bromo ester with arylzinc and the reduction of chiral ester to diol with a tertiary carbon atom. Moreover, it was demonstrated that our enantioselective Negishi cross-coupling was a powerful tool to construct stereogenic benzylmethyl center in chiral drugs on a gram scale.


2014 ◽  
Vol 50 (38) ◽  
pp. 4901-4903 ◽  
Author(s):  
Sandra Börding ◽  
Thorsten Bach

The C24–C40 fragment of (−)-pulvomycin was prepared in enantiomerically pure form using a concise synthesis method (15 linear steps from d-fucose, 6.8% overall yield) featuring a diastereoselective addition to an aldehyde, a β-selective glycosylation and a Stille cross-coupling as the key steps.


1983 ◽  
Vol 48 (16) ◽  
pp. 2767-2769 ◽  
Author(s):  
Vishnu K. Tandon ◽  
Albert M. Van Leusen ◽  
Hans Wynberg

2013 ◽  
Vol 62 (1) ◽  
pp. 217-219 ◽  
Author(s):  
G. Yu. Ishmuratov ◽  
M. P. Yakovleva ◽  
G. R. Mingaleeva ◽  
M. A. Shutova ◽  
R. R. Muslukhov ◽  
...  

Synthesis ◽  
2018 ◽  
Vol 50 (13) ◽  
pp. 2490-2515 ◽  
Author(s):  
Yu Yamashita ◽  
Yoichi Hirano ◽  
Akiomi Takada ◽  
Hiroshi Takikawa ◽  
Keisuke Suzuki

This is a full account of our synthetic endeavor on the total synthesis of bis-anthraquinone antibiotic BE-43472B, an unusual octacyclic aromatic polyketide with a bis-anthraquinone scaffold. Three key steps enabled a facile access to the anthraquinone unit corresponding to the ABCF rings; (1) cyclo-condensation or -addition of benzonitrile oxides with cyclic enone derivatives, (2) benzoin cyclization for the stereoselective ring fusion with an angular hydroxy group, and (3) pinacol rearrangement for stereoselective installation of the angular aryl group. Other keys for the success include, (4) diastereoselective methylation of a lactol derivative, and (5) late-stage installation of the C3 hydroxy group through stereoselective oxirane ring formation via halohydrin derivatives. Whereas oxidation of the double bond in the enone with an adjacent 1,3-diketone moiety failed, the projected oxidation was achieved with the alkene keeping the isoxazole moiety intact as a 1,3-diketone equivalent. In the racemic total synthesis, X-ray crystal structure analysis of the target was achieved, proving the three-dimensional architecture for the first time. The asymmetric total synthesis was also achieved by exploiting a cycloadduct of the nitrile oxide and the enantiomerically pure cyclohexenone, which was convertible to the common intermediate via dehydrogenation followed by alkoxycarbonylation.


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