Reaction of lithium diphenylphosphonium di(methylide) with carbonic acid derivatives. A novel access to polyfunctional unsaturated esters and amides

• Published in: Heteroatom Chemistry
• Main Authors: Cristau, Henri‐Jean, Perraud‐Darcy, Anne, Ribeill, Yves
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1992
• Subjects: Carbonic acid
• Online Access: http://dx.doi.org/10.1002/hc.520030416; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fhc.520030416; https://onlinelibrary.wiley.com/doi/pdf/10.1002/hc.520030416

Abstract The lithium diphenylphosphonium di(methylide) Ph 2 P(CH 2 ) 2 Li 1 readily attacks cyclic carbonates, carbamates, and thiocarbamates, resulting in “pseudo‐acylation” products, after a ring‐opening step. Thus, new stabilized ylides are prepared, which can be used in situ as carbonyl olefination reagents towards aldehydes. This procedure is a new one‐pot method for the synthesis of (E)‐vinylic esters and amides, bearing a free ω‐hydroxyl group. When a thiocarbamate is the initial substrate for 1 , a Michael‐type cyclization occurs, following the Wittig olefination, resulting in the one‐pot preparation of 7‐membered heterocycles.