Stereocontrolled total synthesis of (+)-trans-dihydronarciclasine. 2012

Soonho Hwang, and Deukjoon Kim, and Sanghee Kim
College of Pharmacy, Seoul National University, San 56-1, Shilim, Kwanak, Seoul 151-742, Korea.

A highly stereoselective and efficient total synthesis of trans-dihydronarciclasine from a readily available chiral starting material was developed. The synthesis defines two of the five stereogenic centers of the natural product by an amino acid ester-enolate Claisen rearrangement. The other three stereogenic centers are created in a highly stereocontrolled fashion via a six-ring vinylogous ester intermediate, which is generated from the γ,δ-unsaturated ester functional group of the Claisen rearrangement product in an efficient three-step sequence. This concise total synthesis exemplifies the use of a highly regioselective Friedel-Crafts-type cyclization to form the B ring via an isocyanate intermediate derived from an N-Boc group, which is superior to the conventional method using an imino triflate intermediate. This same N-Boc group is employed to give high selectivity in the Claisen rearrangement earlier in the sequence.

UI MeSH Term Description Entries
D003500 Cyclization Changing an open-chain hydrocarbon to a closed ring. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed) Cyclizations
D004952 Esters Compounds derived from organic or inorganic acids in which at least one hydroxyl group is replaced by an –O-alkyl or another organic group. They can be represented by the structure formula RCOOR’ and are usually formed by the reaction between an acid and an alcohol with elimination of water. Ester
D000470 Alkaloids Organic nitrogenous bases. Many alkaloids of medical importance occur in the animal and vegetable kingdoms, and some have been synthesized. (Grant & Hackh's Chemical Dictionary, 5th ed) Alkaloid,Plant Alkaloid,Plant Alkaloids,Alkaloid, Plant,Alkaloids, Plant
D013237 Stereoisomerism The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed) Molecular Stereochemistry,Stereoisomers,Stereochemistry, Molecular,Stereoisomer
D015394 Molecular Structure The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds. Structure, Molecular,Molecular Structures,Structures, Molecular

Related Publications

Soonho Hwang, and Deukjoon Kim, and Sanghee Kim
June 2017, Journal of natural products,
Soonho Hwang, and Deukjoon Kim, and Sanghee Kim
December 2012, Organic letters,
Soonho Hwang, and Deukjoon Kim, and Sanghee Kim
January 2008, Chemistry (Weinheim an der Bergstrasse, Germany),
Soonho Hwang, and Deukjoon Kim, and Sanghee Kim
January 2018, Monatshefte fur chemie,
Soonho Hwang, and Deukjoon Kim, and Sanghee Kim
December 2012, Angewandte Chemie (International ed. in English),
Soonho Hwang, and Deukjoon Kim, and Sanghee Kim
February 2017, Angewandte Chemie (International ed. in English),
Soonho Hwang, and Deukjoon Kim, and Sanghee Kim
June 2018, Journal of natural products,
Soonho Hwang, and Deukjoon Kim, and Sanghee Kim
March 2008, The Journal of organic chemistry,
Soonho Hwang, and Deukjoon Kim, and Sanghee Kim
August 2004, Proceedings of the National Academy of Sciences of the United States of America,
Copied contents to your clipboard!