| abstract |
14-Me-bicyclo-(19,3,0)-pentadecene- 1(12) having formula (I) is prepd by (A) a phase transfer alkylotion reaction of cyclododecanone (II) with an allyl halide (III) (where X is Cl, Br, or I); (B) O3-dissociation of the 2-(2'-methylene-1'-propyl)-cyclododecanone (IV) obtd to form 2-(2'-oxo-1'-propyl)-cyclododecanone (V): (C) cyolisation of (V) to bicyclo (10,3,0)-pentadeca-15-en-14-one (VI); (D) reaction of (VI), opt after hydrogenation to bicyclo(10,3,0)-pentadecan-14-one, (VIa), with an MeMg halide, to form the new bicyclic alcohols (VII) or (VIIa); (E) dehydration of the alcohols to the new methylated bicyclic cpds. (VIII) or (VIIIa); (F) hydrogenation of the 14-Me-bicyclo (10.3,0)-pentadeca- 1(12).14 -diene (VIII) or G isomerisation of the 14-Me-bicyclo-(10,3,0)-pentadeca-14-ene (VIIIa) by heting with acids. (I) is an intermediate in muscone musk perfume prepn. and allows a simple prepn of muscone. |