| 摘要 |
Ionones, useful as odourants or as intermediates for further syntheses, of formulae: and corresp. alpha- form (Ib) (where R1-5 are H or 1-4 C alkyl) are prepd. by cyclisation of cpds. of formula: with 0.7 - 3.5 kg. HClO4 (calc. as 100% acid) per kg. (Ia)/(Ib) in the form of a 50-70% aqs. soln. wherein, to produce (Ia) as the major product 0.7 - 1.2 kg. 100% HClO4 per kg. (IIb) is used, while 2.8 - 3.5 kg. 100% of (Ib).
|
