98875-57-1Relevant academic research and scientific papers
Mechanism of Formation of Natural Cyclopropanes: Synthesis of Postulated Intermediates in Presqualene and Chrysanthemyl Alcohol Biosynthesis
Boulton, Keith,Shirley, Ian,Smith, Ian H.,Whiting, Donald A.
, p. 1817 - 1824 (2007/10/02)
The α-unsaturated esters (15), (28), and (33) have been used in deconjugative additions to ketones, to provide the β,γ-hydroxy esters (17), (18), (29), (30), and (37) and hence the unsaturated diols (22), (23), and (38).These diols have been postulated as precursors to the natural cyclopropanes chrysanthemyl alcohol and presqualene, through homoallylic participation.Experiments with cell-free extract of Artemisia annua foliage show that neither diol (22) nor (23) is converted to chrysanthemyl alcohol.Limited experiments with an homogenate of Rhizopus arrhizus provide little support for the intervention of the diol (38) in squalene biosynthesis.
Mechanistic Study of the Thermal Acid-catalysed Rearrangement of trans-methyl Chrysanthemate to Lavandulyl Derivatives
Goldschmidt, Zeev,Crammer, Bernard,Ikan, Raphael
, p. 2697 - 2705 (2007/10/02)
trans-Methyl chrysanthemate (17) under acid conditions at room temperature rearranged to the lavandulyl esters: methyl trans-5-methyl-2-propen-2-ylhex-3-enoate (18) and methyl trans-5-methyl-2-(2-hydroxypropan-2-yl)hex-3-enoate (19) which was formed by cyclopropylcarbinylhomoallyl rearrangement.Both (18) and (19) further isomerise and dehydrate to the stable methyl trans-5-methyl-2-propan-2-ylidenehex-3-enoate (20).Under similar acidic conditions, (18) and (19) each gave a mixture of lavandulyl esters and (17); minor amounts of side products, methyl trans-5-methylhex-3-enoate (21), methyl trans-5-methyl-2-(2-methoxypropan-2-yl)hex-3-enoate (22), methyl cis-5-methyl-2-propen-2-ylhex-2-enoate (23) were detected after some time.Acid methanolysis of (17) gave a substantial amount of (22) and its isomer, methyl 2,2-dimethyl-3-(2-methoxypropan-2-yl)cyclopropanecarboxylate (26).There was also found in low concentration, methyl trans-5-methyl-2-propan-2-ylhex-3-enoate (24) and methyl 5-methyl-2-propan-2-ylidenehexanoate (25) possibly the result of a hydride transfer from the solvent.Deuterium exchange was observed in the isobutenyl side-chain of (17) and the isobutenyl moiety of (18) and (19).At 130 deg C under similar acidic conditions a mixture of unsaturated γ- and δ-lactones was obtained from (17).The principal lactone was dihydro-5-propan-2-yl-3-propan-2-ylidenefuran-2(3H)-one (29).Mechanisms for the formation of these products are discussed.The fact that lavandulyl derivatives were obtained may shed new light on the biogenesis of chrysanthemic acid in plants.
SYNTHESIS OF "PRE-PRESQUALENE", A PREDICATED INTERMEDIATE IN PRESQUALENE BIOSYNTHESIS, AND OF PRENYLOGUES.
Shirley, Ian,Smith, Ian H.,Whiting, Donald A.
, p. 1501 - 1504 (2007/10/02)
The synthesis is reported, using deconjugative addition, of the E- and Z- diols (15g) and (16g), postulated intermediates in presqualene biosynthesis.
