-
9
-
-
84985618680
-
-
The CIP system allows the assignment of the configuration of diastereomers in general formulas only when additional postulates are added [5]. For the purpose of rapid assignment to diastereomeric series we therefore use the syn‐anti prefixes of Masamune et al. [6]. If necessary, they are to be defined through structural formulas.
-
-
-
-
15
-
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84985618703
-
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The term “homoaldol addition” implies that the addition of the starting material leads immediately to homoaldols. Therefore, we name versions that require further deblocking steps as “homoaldol reactions”.
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-
-
-
142
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0346955834
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Reaktionen von 1-Nitrosamino-allyllithiumverbindungen. Reversibilität der Carbonyladdition
-
For further allyl anions that can be regarded as homoenolate reagents, see e.g.
-
(1977)
Chemische Berichte
, vol.110
, pp. 2334
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-
Renger, B.1
Seebach, D.2
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155
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84985583314
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Diplomarbeit, Universität Göttingen 1980.
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Hanko, R.1
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164
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0000344737
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Oraganometallic Compounds for Stereoregulated Synthesis of Acyclic Systems. Their Application to the Synthesis of the Prelog-Djerassi Lactonic Acid
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(1982)
HETEROCYCLES
, vol.18
, pp. 357
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Yamamoto, Y.1
Maruyama, K.2
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169
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84985623106
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In contrast, there is a danger of isomerization in all reactions involving the connecting heteroatom.
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176
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84985504850
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Dissertation, Universität Göttingen 1983.
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Brönneke, A.1
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177
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84985566083
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Dissertation in preparation, Universität Göttingen 1985
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van Hülsen, E.1
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181
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84918427926
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syn-Diastereoselektive Homoaldol-Reaktionen: γ-Hydroxyalkylierung von (Z)-2-Butenylcarbamaten und Synthese von β,γ-cis-di- und -trisubstituierten γ-Lactonen
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(1984)
Angewandte Chemie
, vol.96
, pp. 241
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Hoppe, D.1
Lichtenberg, F.2
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186
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33645490551
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Rezepte und Zutaten für kontrollierte CC-Verknüpfungen mit Organometall-Reagentien
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Reviews
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(1974)
Angewandte Chemie
, vol.86
, pp. 751
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-
Schlosser, M.1
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189
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0003409401
-
-
Figure 1 does not take into consideration that the approach of the cation results in a bending of the bond to the C‐1 ligand out of the plane of the allylic system; cf.
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(1982)
Angew. Chem.
, vol.94
, pp. 142
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Schlosser, M.1
Stähle, M.2
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191
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84985513745
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-
The concept of dipole stabilization was introduced by Beak et al. [108, 87]. The term “induced dipole stabilization” refers to the polarization due to the cation [109].
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195
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0001294779
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Dipole-stabilized carbanions: evidence for a complex in the .alpha.'-lithiation of N,N-dimethyl-2,4,6-triisopropylbenzamide
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(1983)
Journal of the American Chemical Society
, vol.105
, pp. 2080
-
-
Al‐Aseer, M.1
Beak, P.2
Hay, D.3
Kempf, D.J.4
Mills, S.5
Smith, S.G.6
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206
-
-
84985593642
-
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2Al) the energy difference between equatorial and axial carbamoyloxy groups in the transition state is the dominant factor.
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-
-
-
207
-
-
84985592682
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Racemates; one enantiomer has been arbitrarily selected to denote the relative configuration.
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-
-
-
209
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84970549066
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Organotitanium reagents in organic synthesis a simple means to adjust reactivity and selectivity of carbanions
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Review
-
(1982)
Top. Curr. Chem.
, vol.106
, pp. 1
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Reetz, M.T.1
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210
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84985504841
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-
Reviews: see [55].
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-
-
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211
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84985572457
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-
The product ratios are kinetically controlled; we have never obtained any indication of equilibration.
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-
-
-
218
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-
0000841268
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Reetz [121] has in many cases observed an influence of the leaving group in the reagent 150 on the selectivity and postulated the formation of “ate” complexes; cf. also:,. Where tested, we obtained identical results with the chloride 150c and the isopropoxide 150d; only in the case of 150d is the metal exchange slower, which led us to a false interpretation [126]
-
(1982)
Tetrahedron Lett.
, vol.23
, pp. 5259
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-
Reetz, M.T.1
Wenderoth, B.2
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221
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0000189945
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A case of highly diastereoselective addition to unsymmetrical ketones:lk-addition of (2-alkenyl)triphenoxytitanium derivatives
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Further examples:, and ref. [55]
-
(1982)
Helvetica Chimica Acta
, vol.65
, pp. 1972
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-
Seebach, D.1
Widler, L.2
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222
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84985169948
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Results so far obtained allow two hypotheses: titanium compounds of this type are not formed on exchange, or else they react with low selectivity. Z/E‐isomerization is slow (Table 1); cf. also
-
Chem. Lett.
, vol.1983
, pp. 219
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-
Mashima, K.1
Yasuda, H.2
Asami, K.3
Nakamura, A.4
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223
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84985624013
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-
The reason may be an improved α‐selectivity of the exchange. Moreover, the hydride is commercially available in higher purity than the chloride.
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-
-
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234
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-
84985566081
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-
We previously assumed the opposite relative configuration [113].
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-
-
-
236
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84985512760
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-
Dissertation in preparation, Universität Göttingen 1985.
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-
-
Gonschorrek, C.1
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238
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84985592719
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-
That the rearrangement takes place largely with retention of configuration at C‐3 rather than with inversion is still speculative.
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-
-
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252
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84985513416
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Diplomarbeit, Universität Göttingen 1984.
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-
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Lüssmann, J.1
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253
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84985532941
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Diplomarbeit in preparation, Universität Göttingen 1985.
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-
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Tarara, G.1
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258
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-
84985529568
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-
The (2E)‐configuration of 203 has been verified by 1‐silylation.
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-
-
-
267
-
-
84985583393
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-
Provided that it does not racemize under the reaction conditions, the (S)‐aldehyde should give the adducts 206 and 207 in enantiomerically pure form.
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-
-
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268
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84985583383
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-
Diplomarbeit, Universität Göttingen 1984.
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Wilckens, M.1
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274
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84985587502
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Chelat- oder Nicht-Chelat-Kontrolle bei Additionsreaktionen von chiralen α- und β-Alkoxycarbonyl-Verbindungen
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Review
-
(1984)
Angewandte Chemie
, vol.96
, pp. 542
-
-
Reetz, M.T.1
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277
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84985524103
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-
Dissertation, Universität Göttingen 1983.
-
-
-
Hanko, R.1
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285
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0001694676
-
-
For a new method for the anti‐selective homoaldol reaction with (E)‐1‐tetrahydropyranyloxy‐2‐butenyl boronates, and for an indirect syn‐selective version; cf.
-
(1984)
Tetrahedron Lett.
, vol.25
, pp. 4491
-
-
Moret, E.1
Schlosser, M.2
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