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COMNIUNtCATIONSsities were registered to 25 = 5 0 ' . Of 8639 reflections, 5330 were independent (R,,, = 0.0406). An absorption correction based on $ scans was applied. The structure was solved with the heavy atom method and refined against F2 . Methyl H atoms were included by using rigid groups, all other H atoms with a riding model. Final w3R2 = 0.0732 based on F2 for all data, conventional R(F) 0.0309, for 360 parameters and 162 restraints; max. A p 955 enm-3 Crystallographic data (excluding structure factors) for the structure reported in this paper have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication no CCDC-100 177. Copies of the data can be obtained free of charge on application to The Director, CCDC, 12 Union Road, Cambridge CB2 lEZ, UK (fax: int. code +(1223) 336-033; e-mail: deposit($chemcrys.cam.ac.uk). 1161 A. Holm, J. J. Christiansen, C. Lohse, J Chem. Soc. Perkrn Puns. 1 1979, 960 [17] The "C NMR resonance signals of comparable 3-aryl-4,5-di(methyloxycar-bony1)isothiazole derivatives also fall in this range; see for example: P. A. Brownsort, R. M. Paton.

A concept for the homogeneous hydroformylation of internal olefins to linear aldehydes is presented. The internal olefin is isomerized to its terminal isomer by one catalyst prior to hydroformylation by a second transition metal catalyst. The terminal olefins obtained by isomerization react preferentially to give linear aldehydes. The viability of the concept is demonstrated by a dual catalytic Ru/Rh system with chelating phosphanophosphite ligands. Thus, the isomerization ± hydroformylation sequence represents a promising starting point for the economically important refinement of internal olefins.

Three palladium‐catalyzed steps (allyl alkylation, Wacker oxidation, and carbonylative cross‐coupling) characterize the first asymmetric total synthesis of 1, a component of plant extracts used as contraceptives.