- Unprecedented one-pot, domino tertiary alcohol protection-Michael type addition of halides to Morita-Baylis-Hillman adduct of isatin with RCOX/K2CO3: diastereoselective synthesis of oxindole appended β-halo esters.
Unprecedented one-pot, domino tertiary alcohol protection-Michael type addition of halides to Morita-Baylis-Hillman adduct of isatin with RCOX/K2CO3: diastereoselective synthesis of oxindole appended β-halo esters.
Organic letters (2013-03-07)
Rajarethinam Solaiselvi, Ponnusamy Shanmugam, Asit Baran Mandal
PMID23461280
ABSTRACT
A facile method utilizing RCOX/K2CO3 as a novel reagent for conjugate addition of hydrogen halide, in addition to tertiary (3°)-hydroxyl protection that leads to the synthesis of functionalized β-halo Morita-Baylis-Hillman ester appended oxindoles, has been developed. The diastereoselective one-pot O-acylation-hydrohalogenation observed cannot otherwise be performed by treatment with hydrohalide. Deprotection of a 3°-hydroxyl protecting group has also been demonstrated by treatment with hydrochloric acid.
MATERIALS
Product Number
Brand
Product Description
Sigma-Aldrich
Hydrochloric acid, meets analytical specification of Ph. Eur., BP, NF, fuming, 36.5-38%
Sigma-Aldrich
Hydrochloric acid, puriss. p.a., ACS reagent, reag. ISO, reag. Ph. Eur., fuming, ≥37%, APHA: ≤10
Supelco
Hydrogen chloride - 1-butanol solution, ~3 M in 1-butanol, for GC derivatization, LiChropur™