1. Haouamines A and B: A New Class of Alkaloids from the Ascidian Aplidium haouarianum
2. In the original text: “.isomer I could have a stereochemistry as represented in Figure.” This accurate NMR study(1)reasonably doesn’t claim that the obtained ROESY correlations indicate a sole geometry of the tetrahydropyridine ring ofM1in solution. Indeed, these experimental NOE-based data are compatible with a1Sf and Sf1sofa as well as a1H6half-chair conformation (seeSupporting Information).
3. Concerning rotation, it is discussed(1)as “atropoisomerism of the 3-aza-[7]-paracyclophane system”. This description of rotation may be interpreted only as rotation of ring B. Geometries, which result from the proposedrotation or N-inversion inC1, are not specified in ref1. The only source of structuresC3orC2/C4are the present calculations. On the other hand, formally, these structures may be obtained via rotation of ring B or N-inversion, respectively (Figure2; see Figure3for similar structures). No other conformers, which could appear as a result of these intramolecular motions, e.g., additional ring B rotamers, have been located (this work). Thus, conformersC2,C3,C4, etc. correspond to general structures implied in ref1. In fact, rotation of ring B is sterically hindered (seeSupporting Informationfor details). However, consideration of interconversionsC1⇌C3,C5⇌C7, etc. cannot be withdrawn. For instance, additional calculations show that this ring rotation might result from a sequence of intramolecular chemical transformations which provide interconversionC1⇌C3(see Supporting Information). Other, unexpected mechanisms couldn’t be excluded. Thus, ISRfin Figures2and3means formal rotation of phenolic ring B.
4. aAnet, F. A. L.InConformational Analysis of Cyclohexenes, Cyclohexadienes and Related Hydroaromatic Compounds;Rabideau, P. W., Ed.VCH Publishers:New-York, 1989; pp3−45.