137653-98-6Relevant academic research and scientific papers
SINTESIS ENANTIOSELECTIVA DEL FRAGMENTO C9-C13 DE LA ERITROMICINA B
Dominguez, E.,Carretero, J. C.
, p. 397 - 402 (2007/10/02)
A stereocontrolled synthesis of the enantiomerically pure C9-C13 fragment of erythromycin B is described.The process takes place in 15 steps from (R)-phenylsulfonyl p-tolylsulfinyl methane and butyraldehyde (16percent overall yield).The key steps, corresponding to the formation of the chiral centers, are based on the iterative synthesis of γ-hydroxyvinylsulfones and further syn-stereoselective addition of MeLi to their protected derivatives.
Lipase-Catalyzed Kinetic Resolution of γ-Hydroxy Phenyl Sulfones
Carretero, Juan C.,Dominguez, Esteban
, p. 3867 - 3873 (2007/10/02)
Lipase PS (from Pseudomonas cepacia) catalyzed the enantioselective transesterification of racemic γ-hydroxy-α,β-unsaturated phenyl sulfones 1 and their α,β-saturated derivatives 3 with vinyl acetate in an organic solvent (usually iPr2O).Remarkably, in substrates 1 with (E)-stereochemistry, the enantioselectivity of the process was little influenced by the nature of the R chain.Hence, very high enantiomeric ratios (E>/=45) were observed in substrates 1 bearing short (R = Me or Et), long (R = n-C6H13 or n-C10H21), bulky (R = iPr), or functionalized R chains.The (R)-enantiomer was the fast-reacting enantiomer in all cases.Concerning the reactivity, the rate of the reaction decreased significantly with an increase in size of length of the R chain (reaction time for 50percent conversion from 3.5 to 162 h).Less satisfactory enantioselectivities (E = 5-48) were obtained when the saturated substrates 3 were used instead of the corresponding α,β-unsaturated alcohols 1.
