Synthesis of (1S,2S)- and (1R,2R)-1-amino-2-methylcyclopropane-phosphonic acids from racemic methylcyclopropanone acetal

An efficient and easy one-pot reaction from readily available racemic alkylcyclopropanone acetals gave the corresponding amino phosphonates with excellent diastereoselectivity. After catalytic hydrogenolysis, and hydrolysis, these trans-phosphonates led to enantiopure (+)-1-amino-2-methylcyclopropanephosphonic acid and its antipode (analogues of allo-norcoronamic acid). (C) 2002 Elsevier Science Ltd. All rights reserved.