Andrea Gambini

Carbocyclic serine analogues: regio- and diastereoselective syntheses of new 1-amino-2,5-dihydroxycyclohexanecarboxylic acids

Abstract Spirooxazolones 3 , obtained by Diels–Alder reaction between oxazolone 1 and dienes 2 , are the key starting materials for the preparation of β-hydroxycyclohexenamino acid derivatives 4 – 6 . The regio- and diastereoselective functionalization of cyclohexyl ring with a second hydroxy group to give the new 1-amino-2,5-dihydroxycyclohexanecarboxylic acids 11 , 19 and the 2,4-dihydroxy derivative 20 was achieved when starting from compounds 4 – 6 . In fact, the iodo-oxazination reaction on compounds 4 , followed by reduction of the iodine atom, led to the dihydroxyamino acids 11 in which the cis relationship exists between the two hydroxy groups. The iodo-lactonization reaction, followed by reduction of the iodine atom, allowed for the formation of the trans dihydroxy derivatives 19 starting from the acids 5 .