L A Walter, W K Chang J Med Chem. 1975 Feb;18(2):206-8. doi: 10.1021/jm00236a022.
1,5-Ethano-2,3,4,5-tetrahydro-1H-3-benzazepine, from the LiA1H4 reduction of 2-benzyloxy-1,5-ethano-4-oxo-2,3,4,5-tetrahydro-1H-3-benzazepine, was converted to N-alkyl, aralkyl, cycloalkyl, and alkenyl derivatives which were inactive as morphine type analgetics in mice. The LiA1H4 reduction of 2-benzyloxy-1,5-etheno-4-oxo-2,3,4,5-tetrahydro-1H-3-benzazepine gave unstable products from which only the skeletally rearranged dihydro- and tetrahydrobenzo[e]isoindolines, were isolated.
2. Synthesis of 2,3,4-Trideoxy-2,3,4-trifluoroglucose
Lucas Quiquempoix, Zhong Wang, Jérôme Graton, Peter G Latchem, Mark Light, Jean-Yves Le Questel, Bruno Linclau J Org Chem. 2019 May 3;84(9):5899-5906. doi: 10.1021/acs.joc.9b00310. Epub 2019 Mar 28.
There is an increasing interest in investigating how polyfluorination of carbohydrates modifies their physical and biological properties. An example that has caught much attention is 2,3,4-trideoxy-2,3,4-trifluoroglucose. Four syntheses of this compound have been reported, which are either low yielding or long (13 or more steps). We report a 6-step synthesis of 2,3,4-trideoxy-2,3,4-trifluoroglucose starting from levoglucosan. The solution-phase structure of an intermediate, 1,6-anhydro-2,4-dideoxy-2,4-difluoroallose, features a rare example of a bifurcated F···H(O)···F hydrogen bond and is compared to its crystal structure.
3. Ring Enlargement of N-Phosphanyl-1,2,3,4-tetrahydroquinazolines
Anatoliy Marchenko, Georgyi Koidan, Anastasiia N Hurieva, Svitlana Shishkina, Eduard Rusanov, Aleksandr Kostyuk J Org Chem. 2020 Nov 20;85(22):14467-14472. doi: 10.1021/acs.joc.0c00750. Epub 2020 Sep 4.
We found that 1-phosphanyl-1,2,3,4-tetrahydroquinazolines undergo ring enlargement. Their treatment with trifluoroacetic or hydrochloric acid afforded diazaphosphepinium salts. Deprotonation of these salts gave the corresponding neutral diazaphosphepines. The reaction of 1-phosphanyl-1,2,3,4-tetrahydroquinazolines with diazomethane or phenylazide afforded triazaphosphocine derivatives via insertion of P-N moiety. At the same time, an analogous hexahydropyrimidine derivative reacted with phenylazide in a normal manner at the phosphorus atom to afford the P(V) derivative.