Baldelli Eleonora, Battaglia Arturo, Bombardelli Ezio, Carenzi Giacomo, Fontana Gabriele, Gambini Andrea, Gelmi Maria Luisa, Guerrini Andrea, Pocar Donato
Istituto CNR per la Sintesi Organica e Fotoreattività I.S.O.F., Area della Ricerca di Bologna, Via P. Gobetti 101, 40129 Bologna, Italy.
J Org Chem. 2003 Dec 12;68(25):9773-9. doi: 10.1021/jo0347112.
14beta-Hydroxybaccatin III, a compound with limited availability by natural sources, is the starting material for the synthesis of the second-generation anticancer taxoid ortataxel. The 7-tert-butoxycarbonyl (1a) and 7-triethylsilyl (1b) derivatives of 14beta-hydroxybaccatin III 1,14-carbonate were synthesized from 10-deacetylbaccatin III (3). The crucial steps were (a) the C(14)beta hydroxylation of the corresponding 13-oxobaccatin III derivatives by oxaziridine-mediated electrophilic oxidation and (b) the reduction of the C(13) carbonyl group with sodium or alkylammonium borohydrides. This protocol provides a practical way for the semisynthesis of ortataxel from 10-deacetylbaccatin III, a compound readily available from various yews.
14β-羟基巴卡亭III是一种天然来源可得性有限的化合物，是合成第二代抗癌紫杉烷类药物奥他赛的起始原料。14β-羟基巴卡亭III 1,14-碳酸酯的7-叔丁氧羰基（1a）和7-三乙基硅基（1b）衍生物由10-脱乙酰巴卡亭III（3）合成。关键步骤为：（a）通过氮杂环丙烷介导的亲电氧化对相应的13-氧代巴卡亭III衍生物进行C(14)β羟基化，以及（b）用硼氢化钠或烷基铵硼氢化物还原C(13)羰基。该方法提供了一种从10-脱乙酰巴卡亭III半合成奥他赛的实用途径，10-脱乙酰巴卡亭III可从多种紫杉中轻易获得。
