Toshiyuki Murayama

Diastereoselective synthesis of a key intermediate for the preparation of tricyclic β-lactam antibiotics

Abstract Asymmetric synthesis of ( S )- 5 has been accomplished with an excellent enantiomeric excess by hydrogenation of racemic 5 using ruthenium-BINAP-diamine-KOH system, followed by oxidation. Magnesium enolate of (2 S )-2-methoxycyclohexanone [( S )- 5 ] reacts with the 4-acetoxyazetidinone 4 to give the key intermediate 3 with high yield and diastereoselectivity for the synthesis of sanfetrinem 1 .

A convenient preparative method for β-lactams from β-amino acids using sulfenamide/triphenylphosphine

Abstract β-, γ-, and δ-Amino acids were easily cyclized in high yields to corresponding β-, γ-, and δ-lactams by treatment with N -alkyl-2-benzothiazolylsulfenamide and triphenylphosphine.

A simple and highly diastereoselective synthesis of a 1β-methylcarbapenem key intermediate by deallyloxycarbonylation using palladium complexes

Abstract A Simple, highly diastereoselective synthesis of the key 1β-methylcarbapenem intermediate 1 has been accomplished via a palladium catalyzed deallyloxycarbonylation of diallyl malonate derivative 4a which was readily prepared from (3S,4R)-4-acetoxy-3-[(R)-1-(t-butyldimethylsilyloxy)ethyl]-2-azetidinone 2 in two steps.