Enantioselective Synthesis of Deoxymannojirimycin Based on Sharpless Asymmetric Epoxidation of a Highly Functionalized Allylic Alcohol

2011 ◽  
Vol 2011 (15) ◽  
pp. 2777-2780 ◽  
Author(s):  
Marie-Céline Lamas ◽  
Max Malacria ◽  
Serge Thorimbert
Keyword(s):  
Enantioselective Synthesis ◽  
Allylic Alcohol ◽  
Asymmetric Epoxidation ◽  
Sharpless Asymmetric Epoxidation

Enantioselective Synthesis of 4-Amino-3-hydroxybenzopyran Flavanol Derivatives from Chalcones

Synthesis ◽  
2018 ◽  
Vol 50 (24) ◽  
pp. 4796-4808 ◽  
Author(s):  
Leslie Aldrich ◽  
Qiwen Gao ◽  
Lianyan Xu ◽  
Vincent Parise ◽  
Yash Mehta
Keyword(s):  
Biological Evaluation ◽  
Enantioselective Synthesis ◽  
Allylic Alcohol ◽  
Nucleophilic Aromatic Substitution ◽  
Asymmetric Epoxidation ◽  
Aromatic Substitution ◽  
Chemical Library ◽  
Epoxy Alcohols ◽  
Sharpless Asymmetric Epoxidation

A concise method that is easily amenable for analogue synthesis has been developed to enantioselectively access 4-amino-3-hydroxybenzopyrans from chalcones. Epoxy alcohols were formed from chalcones through a Corey–Bakshi–Shibata reduction of the enone and subsequent Sharpless asymmetric epoxidation of the allylic alcohol. The epoxy alcohols were protected, regioselectively opened with various amines using catalytic europium(III) triflate, and the resulting free alcohols were orthogonally protected. Concomitant deprotection and intramolecular nucleophilic aromatic substitution provided the benzopyran core, which is poised to undergo additional reactions to provide a diverse chemical library with ideal properties for biological evaluation.

A short enantioselective synthesis of 3-epi-jaspine B and (+)-oxybiotin via an intramolecular tandem desilylation oxa-Michael addition strategy

RSC Advances ◽  
2014 ◽  
Vol 4 (91) ◽  
pp. 49770-49774 ◽  
Author(s):  
Anil M. Shelke ◽  
Varun Rawat ◽  
Arumugam Sudalai ◽  
Gurunath Suryavanshi
Keyword(s):  
Michael Addition ◽  
Addition Reaction ◽  
Enantioselective Synthesis ◽  
Asymmetric Epoxidation ◽  
Michael Addition Reaction ◽  
New Synthesis ◽  
Sharpless Asymmetric Epoxidation ◽  
Jaspine B

A new synthesis of cytotoxic 3-epi-jaspine B (34.7% overall yield; 97% ee) and (+)-oxybiotin (21.2% overall yield; 97% ee) is described starting from cis-2-butene-1,4-diol. The key reactions employed in the synthesis are Sharpless asymmetric epoxidation and a novel tandem desilylation-oxa Michael addition reaction.

Improved synthetic route to enantiomerically pure samples of the tetrahydropyran-2-ylacetic acid core associated with the phytotoxic polyketide herboxidiene

2000 ◽  
Vol 53 (8) ◽  
pp. 659 ◽  
Author(s):  
Martin G. Banwell ◽  
Malcolm D. McLeod ◽  
Rajaratnam Premraj ◽  
Gregory W. Simpson
Keyword(s):  
Natural Product ◽  
Phosphine Oxide ◽  
Enantiomeric Excess ◽  
Allylic Alcohol ◽  
Asymmetric Epoxidation ◽  
Ring Cleavage ◽  
Synthetic Route ◽  
Enantiomerically Pure ◽  
Sharpless Asymmetric Epoxidation ◽  
Ylacetic Acid

The phosphine oxide (2), which embodies the tetrahydropyran-2-ylacetic acid core associated with the phytotoxic polyketide herboxidiene (1) and which is a key intermediate in a projected synthesis of this natural product, has been prepared in a highly enantio- and diastereo-selective manner. The pivotal steps in this new and improved synthesis of compound (2) involve Katsuki–Sharpless asymmetric epoxidation of the allylic alcohol (4) to give epoxide (7) and subsequent ring-cleavage of the latter compound with trimethylaluminium to give diol (9). The derived acetate (10) is then readily ozonolysed to give the previously reported aldehyde (11), although now in high enantiomeric excess. Compound (11) can be elaborated, by established chemistry, to the target oxide (2).

Facile synthesis of the enantiomers of frontalin

1984 ◽  
Vol 62 (11) ◽  
pp. 2148-2154 ◽  
Author(s):  
B. D. Johnston ◽  
A. C. Oehlschlager
Keyword(s):  
Asymmetric Epoxidation ◽  
Facile Synthesis ◽  
Epoxidation Reaction ◽  
Synthetic Sequence ◽  
Sharpless Asymmetric Epoxidation

S-(−)- and R-(+)-frontalin (1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane) were prepared from (E)-2-methyl-2,6-heptadiene-1-ol utilizing the Sharpless asymmetric epoxidation reaction to induce chirality. The six-step synthetic sequence proceeded in approximately 50% overall yield and was found to be suitable for the preparation of multi-gram quantities of either enantiomer with ≥ 90% ee.

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