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drolysis, affording the enone 18 as a 64:36 mixture of E to Z isomers in 59% yield. The crucial ring closure of 18 via oxyselenation furnished, after reductive workup, the desired tetrahydropyran-Cone 19 in 78% yield along with 6% yield of its epimer. In stark contrast to the result with a model system,88 the stereochemical outcome of this cyclization proved to be independent of the starting olefin geometry (19 and its epimer: 79% and 5% from E-18; 80% and 6% from 2-18), implying that cyclization proceeded through the chair-preferred transition state involving a stable open carbocation allowing rotation about C-12/C-13 bond to direct the methyl group a t an axial position.

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We are grateful to Profewr Faulkner for providing copies of the proton NMR spectra of the diacetates of udoteatrial and the triacetate of the LAH reduction product.

A Conformationally Restrained Series of AT1-Selective Angiotensin II Antagonists.-The desired target compounds (VI) are restrained analogues of known AII receptor antagonists. The optimal products are the dihydroindanyl derivatives (a series). -(CARPINO, P. A.; SNEDDON, S. F.; DA SILVA JARDINE, P.; MAGNUS-AYRITEY, G. T.; RAUCH, A. L.; BURKARD, M. R.; Bioorg. Med. Chem. Lett. 4 (1994) 1, 93-98; Dep. Med.