Browsing by Author "Turner, Richard B."
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Item Investigation of a tricyclic bridged system related to phyllocladene(1960) Hildebrand, Ernest Gaill; Turner, Richard B.Item Mechanism of the rearrangement of 17[alpha]-Hydroxy-20-ketosteroids: The reaction of compound L-monoacetate with aluminum isopropoxide(1954) Park, King Travis; Turner, Richard B.Item Preliminary studies in the total synthesis of verrucarol(1967) Renold, Walter; Turner, Richard B.A preliminary investigation was undertaken to find a route to the cis A-B ring fusion of the sesquiterpene alcohol verrucarol. To synthesize the desired cis-lactone (47), methylacetoacetate (60) was alkylated with methyl-2-bromopropionate (62) to give compound (64). Michael addition of (64) with methylvinylketone yielded (66). Acid catalyzed cyclization of (66) gave the unsaturated ketodiester (67). Although a second isomer, structure (68), could also be obtained; sodium borohydride reduction of (67) gave a 1,4-reduction leading to the saturated y-lactone (69) and not to the lactone (70). This reduction was confirmed by catalytic hydrogenation of (67) to the saturated ketodiester (75) and subsequent sodium borohydride reduction of (75) leading also to compound (69). Furthermore, the saturated ketodiester (75) was hydrolyzed and decarboxylated to the mono acid (76) which was converted to its corresponding methylester (77), hence also excluding the formation of compound (68) in the acid catalyzed cyclization. Meerwein-Ponndorf-Verley reduction on compound (67) failed to give the unsaturated lactone (46), which could have been equilibrated to the desired cis isomer (47).Item Stereochemical studies of the C.1 methyl group in the trans-1-methyl-2, 8-dioxo-decahydronaphthalene systems(1967) Miller, Russell Bryan; Turner, Richard B.A study was carried cut to determine the relative stereochemistry of the thermodynamically most stable isomer of the l-methyl-2,8-dioxodecahydronaphthalene system. This study was prompted by an apparent ambiguity in the stereochemical assignment of the C.Item Studies in terpene synthesis: a model investigation(1964) Guin, Henry Wayne; Turner, Richard B.In an attempt to find a feasible synthetic route to the C/D ring system in the terpene kaurene and the terpene alkaloids veatchine and garryine a model synthesis was undertaken. The benzal derivative (1) of 1-hydrindanone on alkylation with methallyl iodide gave (2). The stereochemistry of the ring fusion of (2) was not established, but may be considered to be cis by analogy to similar alkylations. Ozonolysis of (2) gave (3) having carbonyl bands at 5.55, 5.70, and 5.83p. (methylene chloride). Compound (3) was considered to be the anhydride, rather than the expected triketone, on the basis of elemental analysis; and a concerted mechanism, involving the ozonide I, was proposed to account for its formation; and on basic hydrolysis of (3) compound (4), having infrared absorption not unlike that of a diacid, was obtained. Lithium aluminum hydride reduction of (2) gave (5), which formed the acetoxy derivative (6). Ozonolysis of (6) gave (7), which was converted to the diketo alcohol (8) by basic hydrolysis. Compound (8) was converted to the acetate (9), which was considered to be an isomer of (7) by mixed melting point depression, since the infrared spectra of (7) and (9) were identical. More work needs to be done to establish the configuration of (7) and (9). Yields in the reactions were not high enough to merit application of the method in the synthesis of the terpenes considered.Item Synthetic approaches to polycyclic bridged ring compounds(1958) Lee, Robert Elsworth; Turner, Richard B.Item Synthetic routes to atisine(1961) Diana, Guy D; Turner, Richard B.