A series of pyrroles incorporating N-tethered acrylates and related groups has been prepared and examined for their capacity to undergo intramolecular Michael addition reactions to form, in a diastereo- or enantio-selective fashion, the corresponding 8-substituted tetrahydroindolizidine or homologues thereof.

A mixed hardwood stand composed of 53% oak (Quercus spp.), 33% yellow-poplar (Liriodendron tulipifera L.), and 14% other species, was clearcut in 1963. Twenty years later a developing, even-aged stand of predominantly sprout origin is dominated by yellow-poplar, black locust (Robinia pseudoacacia L.), red maple (Acer rubrum L.), and sweet birch (Betula lenta L.). The oaks are a minor and decreasing component. This and other studies suggest that clearcuts on good sites in the Southern Appalachians will be dominated by aggressive intolerant species—mainly yellow-poplar. If a larger oak component is desired, measures to ensure strong advance reproduction and lessen competition from prolific sprouters such as red maple will be necessary. South. J. Appl. For. 10:168-72. Aug. 1986.

Growth response of various species to thinning in even-aged stands of Appalachian mixed hardwoods was predicted with species-specific regression equations. Periodic annual increment over a five-year period was expressed as a linear function of original tree basal area divided by breast height age and a thinning or competition index based on stand basal area. For most species, a combination of stand basal area before and after thinning served as the thinning index; for the five oak species studied, the index was simply stand basal area after thinning. Nonlinear regression equations were formulated to express total tree height as a function of dbh and average height of dominant and codominant white oak. The equations for tree basal area increment and total height may be applied to predict growth after thinning in Appalachian mixed hardwood stands. South J. Appl. For. 10:99-104, May 1986

The title alkaloids, (−)-1, (−)-2, (−)-4 and (+)-5 respectively, have each been prepared from the enantiomerically enriched (74% ee) tetrahydroindolizine 14 which is itself obtained via an organocatalyzed and enantioselective intramolecular Michael addition reaction of the pyrrole 13 incorporating an N-tethered and β,β-disubstituted acrylaldehyde moiety.

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