| 摘要 |
<p>An azetidin-2-one-4-sulfinic acid represented by the formula <IMAGE> is reacted with Pb(OAc)4 in liquid SO2 containing CuII ion to provide isomeric cyclization products of the formulas <IMAGE> +TR <IMAGE> wherein R is e.g. benzyl, phenoxymethyl, benzyloxy, diphenylmethoxy, and R1 is a carboxy-protecting group. The products of the process are useful intermediates for 1-oxa- beta -lactam antibacterials.</p> |
