ENANTIOSELECTIVE APPROACHES TO AMINOCYCLOPENTITOLS - A TOTAL SYNTHESIS OF (-6-EPITREHAZOLIN AND A FORMAL TOTAL SYNTHESIS OF (+)-TREHAZOLIN())

Potent inhibitors of trehalase, such as trehazolin and its congeners, represent an attractive approach to the design of effective new insect control agents. In this report, enantioselective total syntheses of ( -)-6-epitrehazolin and (+)-trehazolin were achieved using the asymmetr ic heterocycloaddition between [(benzyloxy)methyl]cyclopentadiene and the acylnitroso compound arising from in situ oxidation of (S)-mandelo hydroxamic acid with tetrabutylammonium periodate. Further function- a lization of the resulting 3,4,5-trisubstituted cyclopentene, either in volving osmylation or epoxidation of the double bond, efficiently crea ted pentasubstituted cyclopentanes. Introduction of the quaternary car bon in both synthesis targets was achieved via stereoselective osmylat ion of an intermediate 2,3,4,5-substituted 1-methylenecyclopentane.