Enantioselective synthesis of both enantiomers of γ-ionone, γ-damascone, karahana lactone and karahana ether
摘要:
A straightforward enantioselective synthesis of both enantiomers of the title compounds is described starting from enantiopure methyl (2S,6R)- or (2R,6S)-cis-2-hydroxy-gamma-cyclogeraniate. These versatile building blocks are obtained by biomimetic cyclization of methyl (6S)- or (6R)-(Z)-6,7-epoxy-7-methyl-3-(trimethylsilyl)methyl-2-octenoate, respectively. The chiral information was encoded by a highly regioselective Sharpless asymmetric dihydroxylation of the corresponding diene. (C) 2002 Elsevier Science Ltd. All rights reserved.
Enantioselective synthesis of both enantiomers of γ-ionone, γ-damascone, karahana lactone and karahana ether
摘要:
A straightforward enantioselective synthesis of both enantiomers of the title compounds is described starting from enantiopure methyl (2S,6R)- or (2R,6S)-cis-2-hydroxy-gamma-cyclogeraniate. These versatile building blocks are obtained by biomimetic cyclization of methyl (6S)- or (6R)-(Z)-6,7-epoxy-7-methyl-3-(trimethylsilyl)methyl-2-octenoate, respectively. The chiral information was encoded by a highly regioselective Sharpless asymmetric dihydroxylation of the corresponding diene. (C) 2002 Elsevier Science Ltd. All rights reserved.
Synthesis of Two Key Fragments of the Complex Polyhalogenated Marine Meroterpenoid Azamerone
作者:Simon D. Schnell、Anthony Linden、Karl Gademann
DOI:10.1021/acs.orglett.9b00090
日期:2019.2.15
A concise route toward two advanced fragments in the context of the total synthesis of the unique natural product azamerone is reported. Key synthetic features include the enantioselective synthesis of an epoxysilane and its Lewis-acid-induced cyclization and the installation of the pyridazine ring via a formylation/condensation sequence. This route provides strategic insights into the chemistry of phthalazinediols, facilitating synthetic approaches toward this class of natural products.