596159 Disclosed herein is a process for producing a pyripyropene derivative having acyloxy groups in the 1- and 11-positions and a hydroxy group in the 7-position. The process comprises a step in which the hydroxy groups in the 1- and 11-positions of the compound represented by formula (B1) are selectively acylated with an acylating agent in the presence or absence of a base in one to three stages. In a preferred embodiment the process is carried out in an aprotic polar organic solvent selected from dimethylsulfoxide, N,N-dimethylacetamide, acetonitrile, N-methyl-2-pyrrolidinone, N-methyl- 2-piperazinone, and N,N-dimethyl-2-imidazolidinone.
