An expeditious synthesis of (+/-)-desepoxy-4,5-didehydromethylenomycin a methyl ester
[formula: see text] A total synthesis of the racemic methyl ester of desepoxy-4,5-didehydromethylenomycin A has been achieved in six steps with an overall yield of 31% starting from diethyl methanephosphonate. The key steps include the Nazarov cyclization of the dienone 7 leading to the alpha-phosphoryl cyclopentenone 8 and the Horner-Wittig reaction of the latter employed for the introduction of the exocyclic methylene moiety.
Balczewski
P
Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Lodz, Poland.
Mikolajczyk
M