Novel Enantioselective Synthesis of 1,3-Butadien-2-ylmethanols via Tandem Alkylbromide-epoxide Vinylations Using Dimethylsulfonium Methylide
作者:Lilian Alcaraz、Katherine Cox、Andrew P. Cridland、Elizabeth Kinchin、James Morris、Stewart P. Thompson
DOI:10.1021/ol0502329
日期:2005.3.1
The treatment of chiral trans-disubstituted and trisubstituted 2,3-epoxy-1-bromides with an excess of dimethylsulfonium methylide 1 affords the corresponding 1,3-butadien-2-ylmethanols in good to excellent yields via a double one-carbon homologation.
A method for the two six-membered rings annelation to cyclic ketones through two sequential Diels–Alder reactions is presented. Naphtho-annelated cycloalkanes with a variety of unsaturation are accessible by choosing the kind of dienophiles, the order of their use, and dehydrogenation.
Synthesis of tertiary 1,3-butadien-2-ylcarbinols from chromium-catalyzed addition of (4-bromobut-2-ynyl)trimethylsilane to ketones
作者:María Durán-Galván、James R. Hemmer、Brian T. Connell
DOI:10.1016/j.tetlet.2010.07.104
日期:2010.9
The synthesis of 1,3-butadien-2-ylcarbinols containing a tertiary alcohol is achieved by desilylation of (trimethylsilyl)methylallenic alcohols. The latter are obtained via a chromium-catalyzed addition of (4-bromobut-2-ynyl)trimethylsilane to aliphatic or aromatic ketones. The desired adducts are obtained in yields ranging from 21% to 67% for this two-step, one-pot process.