Die sterischen Bedingungen der Fragmentierungsreaktion. II. Teil. Stereoisomere 3‐Aminocyclohexyl‐p‐toluolsulfonate. Fragmentierungsreaktionen, 15. Mitteilung

Abstract

231 0a) X = P-Br-C,H,SO, b) X = P-CH&H,SO, c ) X = NH, d) X = N r N + e) X = N(CH,),+OH--1 7 I 3 I 6,x 4 ( 5 5 '..X Eingehender untersucht wurde bisher die Fragmentierung von cis-und tram-Cyclohexan-l,3-diol-Derivaten, namlich die Mono-p-brombenzolsulfonate 4a und 5a [2], die Mono-9-toluolsulfonate 4b und 5b [3], die 3-Aminocyclohexanole 4c und 5c in Form ihrer Diazonium-Salze 4 d und 5 d [4] und schliesslich cis-3-Hydroxycyclohexyll) Vgl. die Ubersicht heterolytischer Fragmentierungsreaktionen [l].

Photoinduced Electron Transfer Bond Fragmentations

“…Some of the first photofragmentation reactions studied in our laboratory and others involved amino alcohols as donors. − The initially formed radical cations selectively fragment at the C−C bond between the amine and alcohol functions to yield a ketone and an α-amino radical (Figure ). The close relationship between these reactions and the Grob fragmentation − of even-electron species has been noted earlier. , The rate constants for unassisted bond fragmentation have been measured for a number of these compounds (Table , structures 1 − 4 ) and, while the fragmentations are relatively slow (10 4 −10 6 s -1 ), they are found to be accelerated upon addition of base to the system. If the hydrogen of the alcohol group is replaced by deuterium, a primary isotope effect on Φ H /Φ D is observed.…”

Microsomal monooxygenation of the carcinostatic 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea. Synthesis and identification of cis and trans monohydroxylated products

“…The cisand ZrazM-3-hydroxycyclohexylamines were isolated as the oxalate salts by fractional recrystallization from methanol. Melting point (193-194°) of trans agreed with Burckhardt et al (1967). Melting point of the cis product was 141-143°.…”

Diastereoisomeric Salt Formation and Enzyme-Catalyzed Kinetic Resolution as Complementary Methods for the Chiral Separation of cis-/trans-Enantiomers of 3-Aminocyclohexanol

“…Overall, the limited information in the literature regarding the preparation of the cis and trans racemic 3-aminocyclohexanols − has restricted the number of approaches towards the individual enantiomers. In this communication we will discuss how it is possible to access all four enantiomers of 3-aminocyclohexanol 1 − 4 by either selective salt formation or enzymatic kinetic resolution of cis - or trans -Cbz-protected 3-aminocyclohexanols.…”