Nucleophilic additions to 4-substituted snoutanones: getting a measure of long range electrostatic and orbital control of π-face selectivity
Abstract
Pentacyclic ketones 10a–e (snoutan-9-ones) undergo nucleophilic additions with the same facial preference as the corresponding norsnoutanones 9a–e, but with markedly reduced selectivity, revealing the involvement of electrostatic effects in the former and implying the importance of hyperconjugative orbital interactions in determining π-face selectivity in the latter systems.