An alkyl shift
Posted by naturalproductman on September 6, 2013
Richmond Sarpong and co-workers have reported in ACIE on a slick alkyl shift to afford (±)-3-demethoxyerythratidinone and (±)-cocculidine. I may be wrong but in Scheme 7 of the paper: going from intermediates 29 to 30 to 4, there is a loss of the enantioselectivity – the scheme shows that the final product is racemic (+/-) but the precursor 29 has 99% enantiomeric excess. Hmm.