Stereoselective reductions of compound 5, by means of(+)-B-chlorodiisopinocampheylboraned led to 6 with a good selectivity. Intramolecular hetero-Michael cyclization of 13 with NaH in HMPA gave 14 with an excellent selectevity.
借助于(+)-B-
氯二异opinocampheylboraned的化合物5的立体选择性还原得到具有良好选择性的6。在HMPA中用NaH对13进行分子内异Michael环化,得到14的选择性很好。