1 Department of Women’s and Children’s Health, University of Liverpool, First Floor, Liverpool Women's Hospital, Crown Street, Liverpool, L8 7SS, UK 2 Department of Biostatistics, University of Liverpool, Shelley's Cottage, Brownlow Street, Liverpool, L69 3GS, UK 3 Research and Development, Alder Hey Children’s NHS Foundation Trust, Eaton Road, Liverpool, L12 2AP, UK, 4 Oncology Unit, Alder Hey...

The total synthesis of the recently reported marine natural product colombiasin A (1) and determination of its absolute configuration are reported. Two Diels-Alder cycloadditions and a palladium-catalyzed rearrangement are employed as key reactions to construct the tetracyclic framework of the target molecule. The enantioselective synthesis of colombiasin A utilizes Mikami's [(S)-BINOL-TiCl2] c...

Computational studies show that the base-mediated intramolecular Diels-Alder of tryptamine-derived Zincke aldehydes, used as a key step in the synthesis of the Strychnos alkaloids norfluorocurarine and strychnine, proceeds via a stepwise pathway. The experimentally determined importance of a potassium counterion in the base is explained by its ability to preorganize the Zincke aldehyde diene in...

Total syntheses of ent-penicillones A (ent-1) and B (ent-2) from 3,5-dimethylcatechol (3) were accomplished in 10 and 9 synthetic steps, respectively. A carbohydrate-templated asymmetric intramolecular Diels-Alder reaction of a masked o-benzoquinone (MOB) 9 and an aqueous acid-catalyzed intramolecular aldol reaction are the key synthetic steps. In addition, the absolute configurations of the bi...

Helical-chiral double hydrogen bond donor catalysts promote the nitroalkene Diels-Alder reaction in an enantio- and periselective manner. This represents the first asymmetric catalytic nitroalkene Diels-Alder reaction via LUMO-lowering catalysis. To gain an insight into this new process, the substrate scope of our catalyst was investigated by exploiting readily available 5-substituted pentameth...

SIDHU, S. S., and R. J. STANIFORTH. 1986. Effects of atmospheric fluorides on foliage, and cone and seed production in balsam fir, black spruce, and larch. Can. J. Bot. 64: 923-931. Fluoride accumulations and damage symptoms to foliage, cones, and seeds of balsam fir (Abies balsamea (L.) Mill.), black spruce (Picea mariana (Mill.) B.S.P.), and larch (Larix laricina (Du Roi) K. Koch) were monito...

The stephacidin and notoamide natural products belong to a group of prenylated indole alkaloids containing a bicyclo[2.2.2]diazaoctane core. Biosynthetically, this bicyclic core is believed to be the product of an intermolecular Diels- Alder (IMDA) cycloaddition of an achiral azadiene. Since all of the natural products in this family have been isolated in enantiomerically pure form to date, it ...

Landscape configuration and forest structure assume an increasing importance as determinants of animal communities. This paper focused on nocturnal Lepidoptera inhabiting alder patches in the Sila National Park, Italy. According to their shapes, were divided into linear compact ones disentangle roles landscape determining composition Lepidopteran communities at different observation scales. We ...

In the present work, the regioselectivity for a series of Diels–Alder reactions (4 reactions) has beenstudied using hardness, electrophilicity and polarizability of products.Furthermore,thermodynamicand kinetic calculations have been done. In all results predicted pararegioisomer is more favorableregioisomerinthese investigated reactions.All calculations have been done at the DFT-B3LYP/6-31G(d)...