Weitere Beiträge zur Synthese von (+)‐Aspicilin

Abstract

Albert Eschenmoser zum 65. Geburtstag gewidmet (2.VI11.90) Further Contributions to the Synthesis of (+)-AspicilinThere are two reasons to try to find out, whether the initial and final parts of the 'photochemical synthesis' of the ]&membered lichen macrolide (+)-aspicilin (5a) can be improved (cf: Schemes I and 2). This synthesis acts as an indicator for the utility of the earlier introduced photolactonization and as a source of large-ring-sized lactones, objects for computer-assisted conformational analysis.

First Total Synthesis of Grahamimycin A

“…The filtrate was concentrated, and the residue was purified by chromatography (hexane/EtOAc) to afford alcohol 10 (9.61 g, 90%). The 1 H NMR spectrum of 10 was identical with that reported …”

Macrolactonizations in the Total Synthesis of Natural Products

“…Quinkert and collaborators have described an original way to obtain macrolactones in good yield by using photolactonization of o -quinol acetates, which passes through a diene ketene intermediate. This method is illustrated in the total synthesis of (+)-aspicilin (Scheme ). −

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Update 1 of: Macrolactonizations in the Total Synthesis of Natural Products

“…Quinkert and collaborators have described an original way to obtain macrolactones in good yield by using photolactonization of o -quinol acetates, which passes through a diene ketene intermediate. This method is illustrated in the total synthesis of (+)-aspicilin (Scheme ). − …”