The N-tosyl carbamates 4a–e, easily prepared starting from the Baylis–Hillman adducts 3a–e, underwent cyclization carried out with I2/NIS in the presence of NaH, to give the corresponding 2-oxo-1,3-oxazolidines 5a–e in good yield and total stereoselection when the substituent at C-5 is Ar. After the removal of tosyl group, followed by the cleavage of the heterocyclic ring, the a-methyl-a-amino acids 8a,b and 10 were obtained in good yield as hydrochlorides.
Diastereoselective functionalization of Baylis-Hillman adducts: A convenient approach to α-methyl-α-amino acids / Martelli, G.; Orena, Mario; Rinaldi, Samuele; Sabatino, P.. - In: AMINO ACIDS. - ISSN 0939-4451. - 39:(2010), pp. 489-497. [10.1007/s00726-009-0465-y]
Diastereoselective functionalization of Baylis-Hillman adducts: A convenient approach to α-methyl-α-amino acids
ORENA, MARIO;RINALDI, SAMUELE;
2010-01-01
Abstract
The N-tosyl carbamates 4a–e, easily prepared starting from the Baylis–Hillman adducts 3a–e, underwent cyclization carried out with I2/NIS in the presence of NaH, to give the corresponding 2-oxo-1,3-oxazolidines 5a–e in good yield and total stereoselection when the substituent at C-5 is Ar. After the removal of tosyl group, followed by the cleavage of the heterocyclic ring, the a-methyl-a-amino acids 8a,b and 10 were obtained in good yield as hydrochlorides.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
