Synthetic Applications of Baylis-Hillman Chemistry: An Efficient and Solely Stereoselective Synthesis of (E)-.ALPHA.-Methylcinnamic Acids and Potent Hypolipidemic Agent LK-903 from Unmodified Baylis-Hillman Adducts
Microwave-assisted synthesis of the (E)-α-methylalkenoate framework from multifunctionalized allylic phosphonium salts
作者:Lidiane Meier、Misael Ferreira、Marcus M. Sá
DOI:10.1002/hc.21001
日期:——
A convenient and general microwave-assisted method for the synthesis of stereochemicallydefined α-methylalkenoic acids and esters from allylic phosphonium salts in a basic aqueous medium is described. A selective preparation of acids or esters was dependent on the base (NaOH or NaHCO3) employed in the reaction and could be achieved with good to excellent yields under mild conditions in the absence
Samarium Metal Promoted Facile C-Acetylation of Baylis-Hillman Adducts in the Presence of Iron(III) Chloride and Iodine
作者:Xueshun Jia、Shaoyu Li、Jian Li
DOI:10.1055/s-2007-973901
日期:2007.4
A novel and efficient strategy for the C-acetylation of Baylis-Hillman adducts has been described. Promoted by Sm(0)/Ac 2 O/FeCl 3 /I 2 , the present method allows for the efficient con-version of Morita-Baylis-Hillman adducts to their corresponding 2-alkylidene-4-oxoalkanoate derivatives and reduction products.
skeletons of dialkyl sulfates, primary allyl halides, and benzyl bromides were transferred to the α-position of the substrates to provide products in moderate to good yields with a diastereoselectivity of >95% in most cases. Substrates bearing a β-(hetero)aryl substituent gave higher diastereoselectivities than those bearing a linear β-alkyl substituent. The crystal structure of the potassium trifluoroborate
A convenient and facile stereoselectivesynthesis of (E)- and (Z)-trisubstituted alkenes has been achieved by treatment of unactivated Baylis–Hillmanadducts with NaBH4 in the presence of CuCl2·2H2O at room temperature for 15 min.