✦ LIBER ✦
Synthesen von (1R)-cis-3-(2′,2′-Dihalovinyl)-2, 2-dimethylcyclopropan-carbonsäuren via Favorskii-Umlagerung von optisch aktiven Cyclobutanonen
✍ Scribed by Hans Greuter; John Dingwall; Pierre Martin; Daniel Belluš
- Book ID
- 102856647
- Publisher
- John Wiley and Sons
- Year
- 1981
- Tongue
- German
- Weight
- 572 KB
- Volume
- 64
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
Syntheses of (1__R__)‐cis‐3‐(2′,2′‐Dihalovinyl)‐2,2‐dimethylcyclopropane Carboxylic Acids via Favorskii‐rearrangement of Optically Active Cyclobutanones
The cis‐cyclobutanones 7 are resolved by means of optically active amine salts of their sodium hydrogen sulfite adducts. The desired (1__R__)‐cis‐carboxylic acids 9 are obtained from the (+)‐cis‐cyclobutanones 7 via Favorskii‐rearrangement and HX‐elimination. The recycling of undesired (−)‐cis‐cyclobutanones 7 is carried out in good yield by their racemization, thus rendering the total synthesis 1+2→9 chirally economic.