| 摘要 |
<p>Pyrazolidinium ylides (I) are prepd. by reacting diazolidine with R1C(=O)R2 or its ketal, thioketal, acetal. R1 and R2 are same or not, C1-6 alkyl, (substd.) C7-12 arylalkyl or Ph; R3 and R4 form phthalimido gp., are each H and amino-protection gp.. Dissolve 4- (R,S)-(t-butoxycarbonylamino)-3-oxo-1,2-diazolidine 2.01g in MeOH 20ml, add acetone dimethyl acetal 10m mole and d-10-kamposulfonic acid (ca. 5mg) to the above soln., reflux for 1.5hr and conc. under vacuum, recrystallize in the CH2Cl2/ iopropyl ether to give 2.01g of 4-(R,S)-(t-butoxycarbonylamino)3-oxo-1-(dimethylmethylene)-1,2- pyrazolidinium ylide.</p> |
