ライフサイエンスコーパス: oxetane

1 ing the formation of either an epoxide or an oxetane.

2 cyclization of a tosylate led to a bicyclic oxetane.

3 fluorine containing pyrazole derivatives and oxetanes.

4 cidic nucleophiles provide 2,2-disubstituted oxetanes.

5 dic nucleophiles providing 2,2-disubstituted oxetanes.

6 se-constraining oxetane (OXE) modifications [oxetane, 1-(1',3'-O-anhydro-beta-d-psicofuranosyl nucleo

7 A wide variety of oxetane 2,2-dicarboxylates were accessed in high yields,

8 Bromination of the polycyclic oxetane 2,4-oxytwistane (rac-(1R,3S,4R,7S,9R,11S)-2-oxat

9 Phosphoramidate prodrugs of a 2'-oxetane 2-amino-6-O-methyl-purine nucleoside demonstrate

10 A six-step conversion of oxirane 3 to oxetane 9 is reported.

11 omosuccinimide (NBS)-mediated cyclization of oxetane alcohol 17, prepared from readily accessible 2-m

12 The mechanism for the coupling reaction of oxetane and carbon dioxide has been studied.

13 107.6 kJ x mol (-1) for copolymerization of oxetane and carbon dioxide supports this conclusion.

14 alytic systems for the selective coupling of oxetane and carbon dioxide to provide the corresponding

15 g reaction, and by the direct enchainment of oxetane and CO 2.

16 Irida-oxetane and oxo-irida-allyl compounds are isolated, prod

17 is unexpected due to the ring strain of the oxetane and the anticipated facile ring opening retro-ox

18 sed to model the structure of the polycyclic oxetane and to assess the component of total ring strain

19 ctionalized 3-/4-aryl- and alkyl-substituted oxetanes and fused oxetane bicycles.

20 ular Paterno-Buchi cyclization yielding endo-oxetanes and significantly changing the Cope-averaged NM

21 ms inclusively, the combinations of oxirane, oxetane, and tetrahydrofuran are rather extensive and co

22 ches to construct heterocyclic systems using oxetanes are described.

23 Oxetanes are valuable intermediates in organic synthesis

24 trategy was the reverse, i.e., to utilize an oxetane as the framework to construct the larger ring.

25 -conjugate addition producing a stable trans oxetane as the only regioisomer.

26 [2+2]-cycloaddition to form an intermediate oxetane as the turnover-limiting step.

27 Experimental evidence for oxetanes as reactive intermediates in the catalytic carb

28 yl- and alkyl-substituted oxetanes and fused oxetane bicycles.

29 ening can be directed toward the substituted oxetane by the addition of a Lewis acid.

30 lective opening of enantiomerically enriched oxetanes by hydrogen peroxide, conversion of the resulti

31 t and a pyridine oxide, alkynyl oxiranes and oxetanes can be converted into functionalized five- or s

32 A four-membered oxygen ring (oxetane) can be readily grafted into native peptides and

33 t to be characterized, it may enable general oxetane construction via oxa-conjugate addition.

34 developed the first synthesis of the unique oxetane containing diterpene (+)-dictyoxetane.

35 ted for the synthesis of epi-oxetin (26), an oxetane-containing beta-amino acid.

36 ring and further derivatization of preformed oxetane-containing building blocks.

37 The oxetane core is built using a Paterno-Buchi photochemica

38 e bases was modest, the triphosphate of a 2'-oxetane cytidine analogue demonstrated potent intrinsic

39 An oxetane D-ring has been fused to the framework of the hi

40 ring Taxol biobehavior as effectively as the oxetane D-ring.

41 istry are reported, including a collation of oxetane derivatives appearing in recent patents for medi

42 Finally, examples of oxetane derivatives in ring-opening and ring-expansion r

43 rview of the literature for the synthesis of oxetane derivatives, concentrating on advances in the la

44 n numerous studies into the synthesis of new oxetane derivatives.

45 ectivity of chiral phosphoric acid-catalyzed oxetane desymmetrizations were investigated by density f

46 rs, which forms crosslinks with the reactive oxetane ends, thus repairing the network.

47 d D-seco derivatives, and structures with no oxetane equivalent underscores that the four-membered ri

48 o characteristics considered responsible for oxetane function: (1) rigidification of the tetracyclic

49 The selective installation of the oxetane graft enhances stability and activity, as demons

50 Oxetane grafting of the genetically detoxified diphtheri

51 4-acetyl substituent is as important as the oxetane in determining the A ring conformation.

52 Examples of the use of oxetanes in medicinal chemistry are reported, including

53 and the N-methyl-3'T thietane analog of the oxetane intermediate.

54 Oxetane intermediates can be formed when C-C bond format

55 The oxetane is stable to acid and basic conditions, as are a

56 The four-membered D-ring, an oxetane, is one of four structural features regarded to

57 While the source of the oxetane kinetic stability is yet to be characterized, it

58 sly with intramolecular OH transfer along an oxetane-like transition state.

59 ate in the stereospecific elaboration of the oxetane linkage was enone 22, which was susceptible to t

60 n acyl group to the tertiary hydroxyl on the oxetane moiety at C4 of the taxane ring demonstrates tha

61 The oxetane moiety of merrilactone A is fashioned via a Payn

62 Notably, this methodology employs a keto-oxetane motif as a 1,4-dicarbonyl surrogate, which can b

63 Oxetanes offer exciting potential as structural motifs a

64 tility, the process was used to introduce an oxetane or azetidine into heteroaromatic systems that ha

65 a triscarbazole hole-transport group and an oxetane or benzocyclobutene crosslinkable group can be r

66 apparently these have never been applied to oxetanes or larger cyclic ethers.

67 of nucleosides with novel base-constraining oxetane (OXE) modifications [oxetane, 1-(1',3'-O-anhydro

68 ) linked bicyclic building blocks, including oxetanes, piperidines, and azetidines, from their parent

69 The oxetane products were further derivatized, while the rin

70 cycles through a facile Lewis-acid-catalyzed oxetane rearrangement.

71 the effort involved recourse to a strategic oxetane ring (see compound 25).

72 ies of Taxol analogues demonstrates that the oxetane ring clearly operates by both mechanisms.

73 The four-membered oxetane ring has been increasingly exploited for its con

74 The facile formation of the strained oxetane ring provides strong support for the intermediac

75 d cyclic ether, followed by formation of the oxetane ring.

76 ate ligand-protein steric effects around the oxetane ring.

77 collision activation leads to the rupture of oxetane rings and the formation of diagnostic ions speci

78 e an efficient strategy for the synthesis of oxetane rings incorporating pendant functional groups is

79 echanical damage of the network, four-member oxetane rings open to create two reactive ends.

80 The network consists of an oxetane-substituted chitosan precursor incorporated into

81 first dyotropic rearrangement of an epoxide-oxetane substrate.

82 ne, pyrrole, azetidine, tetrahydropyran, and oxetane substructures.

83 ay of sensitive functional groups, including oxetanes, sugar moieties, azetidines, tert-butyl carbama

84 tions, as are a number of literature acyclic oxetanes that could undergo similar retro-oxa-conjugate

85 The formation of oxetane, the reaction intermediate leading to (6-4) addu

86 With the oxiranes and oxetanes, the chloro derivative gave a different behavio

87 vated by substoichiometric concentrations of oxetane, THF, Et(2)O, and diisopropylamine are described

88 ative rates of attack of ammonia on oxirane, oxetane, thiirane, and thietane were determined computat

89 Fragmentation of the oxetane via Lewis acid-activation results in the formati

90 The oxetane was subjected to the mild reagent combination CB

91 ntioselective intramolecular ring-opening of oxetanes with alcohols is catalyzed by (salen)Co(III) co

92 ioenriched alcohols provided enantioenriched oxetanes with complete retention of configuration.