The tandem ring-closing metathesis-isomerization approach to 6-deoxyglycals.
Protected 3,6-dideoxyglycals have been synthesized de novo as single isomers starting from ethyl lactate by using the tandem RCM-isomerization reaction as the key step. Different relative configurations become accessible by addition of vinyl- or allyl-metal compounds to protected lactaldehydes under Cram-chelate or Felkin-Anh control. The concept is exemplified for glycals of L-rhodinose and L-amicetose, as well as for ring-expanded non-natural analogues thereof. This novel approach to glycals is also applicable to the synthesis of disaccharide glycals via a reiterative strategy, as exemplified for the dimer of L-rhodinose and its non-natural ring expanded analogue.
Universität Potsdam, Institut für Chemie, Organische Chemie II, Karl-Liebknecht-Strasse 24-25, Haus 25, 14476 Golm, Germany. bernd.schmidt@uni-potsdam.de
Bernd
B
Schmidt
Anne
A
Biernat
D007536:Isomerism; D015394:Molecular Structure; D010100:Oxygen / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*
D011134:Polysaccharides; D010100:Oxygen