A stereodivergent total synthesis has been executed based on the plausibly misassigned structure of the unusual marine hydrindane mucosin (1). The topological connectivity of the four contiguous all-carbon stereocenters has been examined by selective permutation on the highlighted core. Thus, capitalizing on an unprecedented stereofacial preference of the cis-fused bicycle[4.3.0]non-3-ene syste...

The two oxazolidine rings (A and B) of the title compound, C34H44N2O4, display roughly half-chair conformations, which could be described as twisted on the C-O bond. Together, the fused oxazolidine rings have a butterfly shape, with the H atoms attached to the ring junction C atoms in a cis orientation. The cyclo-hexane rings of both p-menthone fragments display chair conformations. The absolut...

The thylakoid Delta pH pathway is a protein transport system with unprecedented characteristics. To investigate its mechanism, the topology of precursor insertion was determined. A fusion protein comprising a large polypeptide domain fused to the amino terminus of pOE17 (a Delta pH pathway precursor) was efficiently processed by thylakoid membranes. The amino terminus, including the targeting p...

A new iridoid glucoside, cornusoside A (1), and four new natural product iridoid aglycones, cornolactones A-D (2-5), together with 10 known compounds were isolated from the leaves of Cornus florida. The structures of compounds 1-5 were established by interpretation of their spectroscopic data. Cornolactone B (3) is the first natural cis-fused tricyclic dilactone iridoid containing both a five- ...

In the title compound, C(22)H(29)N(3)O(5)S, the pyrrolidine ring is cis-fused to the dihydro-pyran ring. The pyrrolidine and dihydro-pyran rings adopt twist and half-chair conformations, respectively. The mol-ecule is in a folded conformation; the sulfonyl-bound benzene ring lies over the pyrimidine-dione ring, with a weak π-π inter-action [centroid-centroid distance = 3.6147 (4) Å]. A weak int...

The title compound, C(32)H(49)ClO(4), was obtained along with nitrile and lactam products in the POCl(3)-catalysed Beckmann rearrangement from 3β-acet-oxy-12-hydroxyiminoolean-28-olic acid methyl ester. The mechanism of the transformation leading to the title compound remains unclear and requires further investigation. Rings A, B and E are in chair conformations, ring C has a twisted-boat confo...

The title compound, C(15)H(22)O(4), an eremophilane sesquiternoid, was isolated from the roots of Ligularia virgaurea. Both six-membered rings (A and B) adopt chair conformations and the five-membered ring is almost planar (r.m.s. deviation = 0.016 Å). The two methyl and two hy-droxy groups adopt a syn conformation and the A/B ring junction is cis-fused. An intra-molecular O-H⋯O hydrogen bond g...

The structure of an iridolactone isolated from Valeriana laxiflora was established as (4R,4aR,6S,7S,7aS)-6-hydroxy-7-hydroxymethyl-4-methylperhydrocyclopenta[c]pyran-1-one chloroform solvate, C(10)H(16)O(4).CHCl(3). The two rings are cis-fused. The delta-lactone ring adopts a slightly twisted half-chair conformation with approximate planarity of the lactone group and the cyclopentane ring adopt...

A reagent-controlled stereodivergent carbocyclisation of aryl aldimine-derived, photocatalytically generated, α-amino radicals possessing adjacent conjugated alkenes, affording either bicyclic or tetracyclic products, is described. Under net reductive conditions using commercial Hantzsch ester, the radical species underwent a single stereoselective cyclisation to give trans-configured amino-ind...