Reactions of relevance to the chemistry of aminoglycoside antibiotics. Part 13. A novel synthesis of benzyl ethers
作者:Anthony G. M. Barrett、Roger W. Read、Derek H. R. Barton
DOI:10.1039/p19800002184
日期:——
Benzyl ethers were prepared from alcohols by reaction with chloro(phenylmethylene)dimethylammonium chloride and sodium hydrogen telluride in sequence. The salt (1)[Me2NC(R1)OR2Cl–; R1= H, R2= cholest-5-en-3β-yl] and sodium borohydride gave the borane complex of 3β-dimethylaminomethoxycholest-5-ene. Salt (1; R1= Ph, R2= cholest-5-en-3β-yl or 5α-cholestan-3β-yl) and ammonia or hydrazine gave the steroidal
通过依次与氯(苯基亚甲基)二甲基氯化铵和碲化氢钠反应,由醇制得苄基醚。盐(1)[我2 NC(R 1)OR 2氯- ; R 1= H,R 2=胆甾-5-烯-3β-基],硼氢化钠得到3β-二甲基氨基甲氧基胆甾-5-烯的硼烷配合物。盐(1; R 1 = Ph,R 2 =胆甾-5-en-3β-基或5α-胆甾-3β-基)和氨或肼得到甾族苯甲酸酯或苯甲酰肼酸盐。
Conversion of amides and lactams to thioamides and thiolactams using hexamethyldisilathiane
作者:D. C. Smith、S. W. Lee、P. L. Fuchs
DOI:10.1021/jo00081a011
日期:1994.1
Amides and lactams were converted to their corresponding thioamides and thiolactams employing a new protocol using hexamethyldisilathiane (TMS(2)S). Oxophilic promoters were employed to generate Vilsmeier-type intermediates, the most efficient reagents being phosphorus oxychloride, triphosgene, and oxalyl chloride. Thionation of intermediate chloro iminium ions was accomplished in situ with TMS(2)S. Yields were good to excellent for secondary and tertiary amides and lactams while yields for primary systems were poor.