Dedicated to Professor Rolf Huisgen on the occasion of his 85th birthday A total synthesis of the biologically potent jatrophane diterpenes pepluanin A (1) and euphosalicin A (2) is being aimed at. En route to these targets, a concise synthesis of the nonracemic cyclopentane building block 74 was developed. Key steps were a Claisen ± Eschenmoser rearrangement of the enantiomerically enriched allylic alcohol 14 to amide 34 (Scheme 7), a hydroxy-lactonization of 40 to 43 (Scheme 9), followed by translactonization to 72, which was subjected to a Davis hydroxylation to 69 (Scheme 17). Eventually, compound 69 was converted into the enol triflate 74. This material should prove suitable for an annulation of the macrocyclic ring characteristic of the desired jatrophanes 1 and 2. Less-successful approaches are also discussed due to their intrinsically valuable information content.

A substrate controlled asymmetric synthesis is described of a highly functionalized cyclopentanyl vinyl triflate which serves as an advanced intermediate in the total synthesis of the novel multidrug resistance reversing jatrophanes pepluanin A and euphosalicin. Key steps are a Claisen-Eschenmoser rearrangement followed by hydroxy-lactonization, intramolecular trans-lactonization, Davis hydroxylation and regioselective enoltriflate formation.

It is demonstrated here that cells in a suspension culture of an established mammalian cell line release non-dialyzable factors into their growth medium. These factors are capable of promoting the adhesion and spreading of these cells on a generally non-attachable substratum and also promote spreading on an adhering substrate. Evidence is presented which demonstrates that the spreading promotion activity of the condition medium is dependent on the cell density of the culture from which it was derived. Dilution of the conditioned medium results in a proportionate dilution of the spreading promotion activity. The results clearly demonstrate that the production of this spreading promotion factor is continued even in the absence of cell to substrate attachment.

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