Enamine carboxylates as stereodetermining intermediates in prolinate catalysis

Experimental and computational studies probing the nature of intermediates in the α-amination of aldehydes catalyzed by prolinate salts support an enamine carboxylate intermediate in the stereodetermining step.     

Drimenol: A versatile synthon for compounds with trans-drimane skeleton

Several reviews have been published on sesquiterpenes, and on drimane-type sesquiterpenes, going through drimenol and related compounds among others. However, to our knowledge, this is the first review exclusively on drimenol. Although, the main focus is on drimenol as a synthon for other drimane-type compounds, synthetic routes to obtain racemic and (-)-drimenol are summarized, as well as its isolation and determination of its configuration, in the early fifties. The reviewed synthetic routes start from natural (-)-drimenol as chiral synthon in most of cases, nevertheless total syntheses are considered as well. The strategies where racemic drimenol is involved begin with biomimetic cyclization of trans-farnesol. Microbiological procedures to functionalize the A ring of drimenol are also commented. The revision is classified according to the chemical structure of the final product, which mainly correspond to structures of natural occurrence, although other related derivatives are also analyzed.     

Destillationen

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