MACROCYCLES BY OLEFINATION OF DIALDEHYDES WITH 1,3-BIS(DIMETHYLPHOSPHONO)-2-PROPANONE

Conjugated cyclic divinyl ketones containing fifteen and seventeen membered rings have been prepared in a single step by condensation of 1,3‐bis (dimethylphosphono)‐2‐propanone (10) with the dialdehydes 14, 17, 20, and 42 in the presence of hydrogencarbonate in aqueous t‐butyl alcohol at reflux without using high dilution techniques. The more highly unsaturated aldehydes give better yields and ketones 34 and 36, or mixtures of the two, were transformed to muscone (1) and Exaltone® by standard procedures. Civetone (2) was prepared by hydrogenation of 43 in pyridine solution. Dienone 29 appears to be the first α, β‐unsaturated ketone in which one of the β‐vinyl proton resonates at higher field than the corresponding α‐proton. Copyright © 1979 Verlag GmbH & Co. KGaA, Weinheim