温和的还原剂四甲基铵三乙酰氧基硼氢化物以高非对映选择性将无环 P-羟基酮还原为其相应的反二醇。α-烷基取代不会显着影响这些还原的立体选择性。在所有检查的情况下,都获得了良好到极好的非对映异构体均质二醇的产率。这些还原的机制涉及三乙酰氧基硼氢化物阴离子将乙酸盐与底物醇进行酸促进的配体交换。所得氢化物中间体,大概是烷氧基二乙酰氧基硼氢化物,还原近端 OH 0 OH OH 0 Me,NHB(OAc), Mew Me&OR - OR Me he
温和的还原剂四甲基铵三乙酰氧基硼氢化物以高非对映选择性将无环 P-羟基酮还原为其相应的反二醇。α-烷基取代不会显着影响这些还原的立体选择性。在所有检查的情况下,都获得了良好到极好的非对映异构体均质二醇的产率。这些还原的机制涉及三乙酰氧基硼氢化物阴离子将乙酸盐与底物醇进行酸促进的配体交换。所得氢化物中间体,大概是烷氧基二乙酰氧基硼氢化物,还原近端 OH 0 OH OH 0 Me,NHB(OAc), Mew Me&OR - OR Me he
Iterative diastereoselective reduction of hydroxy diketoesters to all 1,3,5 syn triols: synthesis of C1-C10 fragment of Nystatin A1
作者:Carlo Bonini、Giuliana Righi、Leucio Rossi
DOI:10.1016/s0040-4020(01)81196-0
日期:1992.1
the iterative diastereoselective reduction of a model hydroxy 3,5 diketo ester to the corresponding skipped 1,3,5 triol ester was studied in different conditions. The use of NaBH4/Ti(OiPr)4 in THF leads with good stereoselection to the syn-syn triol ester as the main product; the described method has been applied to an extremely short synthesis of the C1-C10 fragment (in racemic form) of the macrolide antibiotic Nystatin A1.