22822-99-7Relevant articles and documents
Nickel-Catalyzed Cross-Electrophile Coupling of Alkyl Fluorides: Stereospecific Synthesis of Vinylcyclopropanes
Erickson, Lucas W.,Lucas, Erika L.,Tollefson, Emily J.,Jarvo, Elizabeth R.
supporting information, p. 14006 - 14011 (2016/11/06)
The stereospecific reductive cross-electrophile coupling reaction of 2-vinyl-4-halotetrahydropyrans for vinylcyclopropane synthesis is reported. The nickel-catalyzed reaction occurs with both alkyl fluorides and alkyl chlorides. To the best of our knowledge, this is the first reported cross-electrophile coupling reaction of an alkyl fluoride. Ring contraction proceeds with high stereospecificity, providing selective synthesis of either diastereomer of di- and trisubstituted cyclopropanes. The utility of this methodology is demonstrated by several synthetic applications including the synthesis of the natural product dictyopterene A. 2-Vinyl-4-fluorotetrahydrofurans also undergo stereospecific ring contractions, providing access to synthetically useful hydroxymethyl cyclopropanes.
Synthesis of dictyopterene A: Optically active tributylstannylcyclopropane as a chiral synthon
Itoh, Toshiyuki,Inoue, Hitomi,Emoto, Sachie
, p. 409 - 416 (2007/10/03)
Synthesis of (IS,2R)-1-[(E)-hex-1-en-1-yl]-2-vinylcyclopropane (dictyopterene A), which was isolated from the essential oil of algae of the genus Dictyopteris in Hawaii, has been demonstrated using optically active tributylstannylcyclopropane as a starting chiral synthon.
Synthesis of Vinylcyclopropanes by Intramolecular Epoxide Ring Opening. Application for an Enantioselective Synthesis of Dictyopterene A
Narjes, Frank,Bolte, Oliver,Icheln, Detlef,Koenig, Wilfried A.,Schaumann, Ernst
, p. 626 - 632 (2007/10/02)
The reaction of functionalized oxiranes 1 with the sulfur- or silicon-stabilized anions 2 provides β-heteroatom-substituted γ,δ-unsaturated epoxides 5 with, for 5e,f, a trans C=C moiety.A cis compound 9 is obtained using acetylide anion 2c via 7 and subse
Diastereoselective cyclopropanations of chiral bicyclic lactams leading to enantiomerically pure cyclopropanes. Application to the total synthesis of CIS-(1S, 3R)-deltamethrinic acid and R-(-)- dictyopterene C
Romo, Daniel,Romine, Jeffrey L.,Midura, Wanda,Meyers
, p. 4951 - 4994 (2007/10/02)
A novel diastereoselective cyclopropanation based on readily available chiral bicylic lactams (1b-c, 6a-b) has provided a number of enantiomerically pure cyclopropanes. Cyclopropanations of unsaturated lactams (10a-h, 12-14) were performed using sulfur ylides as well as a 3+2 cycloaddition-photolysis sequence and furnished the desired cyclopropane adducts (16, 17, 19, 22) in fair to excellent yields. In all cases involving sulfur ylides, cyclopropanations proceeded with a high degree of exo/endo diastereoselectivity (>;90%). However, the mode of addition, exo vs endo, was found to be highly dependent on the angular substituent of the unsaturated lactam. In the case of diazoalkane cycloadditions, high regioselectivity was observed in all cases although exo/endo selectivity was governed by the diazoalkane employed. Diazoisopropane, being more reactive than diazomethane, normally led to lower diastereomeric ratios. Minor diastereomers could be readily removed by chromatography or in most cases by a single recrystallization to provide diastereomerically pure cyclopropyl bicyclic lactams (16, 17, 19, 22). Applications of this methodology to compounds of biological significance was exemplified by an asymmetric, total synthesis of cis-(1S, 3R)-deltamethrinic acid (34) and R-(-)- dictyopterene C′ (42) in high enantiomeric purity.
Signalstoffe und ihre Reception im Sexualcyclus mariner Braunalgen
Jaenicke, Lothar,Boland, Wilhelm
, p. 659 - 670 (2007/10/02)
Lockung und Schreck sind Antworten auf chemische Reize, die bereits von einzelligen Organismen ohne morphologisch abgegrenztes Nervensystem wahrgenommen und verarbeitet werden.Chemische Substanzen loesen Ereignisketten aus, die bei membrangebundenen Signalreceptoren beginnen und ueber regulierende und modulierende Glieder schliesslich die Steuerung motorischer Erfolgsorgane bewirken.Untereinheiten dieser Receptoren werden durch die bindenden Signalstoffe in gegenseitiger Abhaengigkeit konformativ veraendert, chemisch modifiziert und in ihrer molekularen Aktivitaet beeinflusst.Dieses Wechselspiel fuehrt, zusammen mit der eigentuemlichen Motorik, zu einem zielgerichteten physiologischen Verhalten, durch das die begeisselten Geschlechtszellen (Gameten) mariner Braunalgen schliesslich ihren Partner finden koennen.Die einfachen, aber jeweils hochspezifischen Systeme der Braunalgengameten wurden strukturell aufgeklaert und in ihrer biologischen Wirkung analysiert.Bei den Signalstoffen handelt es sich ueberwiegend um Monocyclen mit ungesaettigten Seitenketten (Summenformel z.B.C11H14, C11H16, C11H18).Diese Systeme erleichtern als Modelle das Verstaendnis der komplexen Ganglienschaltungen bei hoeheren Lebewesen, in denen die Sinnesorgane ueber Nervenbahnen dem Zentralnervensystem Nachrichten aus der Umwelt uebermitteln, die dort verarbeitet und, ueber ableitende Bahnen, durch den Bewegungsapparat beantwortet werden.
BIOGENETIC-TYPE SYNTHESIS OF (+/-)-DICTYOPTERENE A, AN ODORIFEROUS SUBSTANCE OBTAINED FROM BROWN SEAWEEDS, DICTYOPTERIS
Yamada, Kiyoyuki,Tan, Hiroaki,Hirota, Keiko
, p. 4873 - 4874 (2007/10/02)
Biogenetic-type synthesis of (+/-)-dictyopterene A (1) was achieved employing 1,cis-5-undecadien-3-ol (2) postulated to be a biosynthetic intermediate of 1: this synthesis means that transformation of dictyoprolene (4) into dictyopterene A (1) was formally made.
