Photochemische Reaktionen. 22. Mitteilun
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J. Iriarte; K. Schaffner; O. Jeger
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Article
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1963
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John Wiley and Sons
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German
⚖ 773 KB
## Abstract The photochemical cyclisation of 11‐keto steroids to 11β, 19‐cyclo‐11‐hydroxy compounds is strongly influenced by steric factors. The presence of a __gem__‐dimethyl group at C‐4 gives rise to a marked improvement in the yield of the cyclic product. The nature of this steric interaction