Synthesis of spirocyclopropanated analogues of iprodine

Methyl 1(tert-butoxycarbonylamino)cyclopropanecarboxylate (9) was converted into the spirocyclopropanated fivemembered ring analogue 7a of Iprodione (1) in five steps with an overall yield of 28 %. The spirocyclopropanated fivemembered ring analogue 8a was prepared from tert-butyl N[1-(hydroxymethyl)cyclopropyl]carbamate (10) in five steps with an overall yield of 19 %. En route to the spirocyclopropanated six-membered ring analogues of Iprodione (1), the oxalic acid diamides 5b and 6b could be obtained starting from 9 or 10 in 33 or 19 % yield, respectively. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005).