(3-hydroxy-1-butenyl) phosphonate 1 with different enzymes has been carried out, and allows the preparation of (S)-1 and (R)-diethyl (3-acetoxy-1-butenyl) phosphonate 2 with very high enantiomeric excess. The absolute conguration of 1 was determined by independent synthesisfrom (S)-ethyllactate.
A straightforward and inexpensive synthetic protocol to access new omega-ketovinyl phosphonates is established from the Lewis or Bronsted acid mediated reactions of alpha-hydroxy allylic phosphonates with aromatic 1,3-diketones. Predominantly, FeCl3 or FeCl3 center dot 6H(2)O has been preferred as easily available, inexpensive and efficient Lewis acid under solvent-free conditions. With experimental and theoretical support, we have demonstrated that some of the substituted open chain 1,3-diketones may exist predominantly in the keto form. Mild base mediated isomerization reactions for omega-ketovinyl phosphonates were carried out to generate corresponding allylic phosphonates. Utility of one of the allylic phosphonates in Horner-Wadsworth-Emmons (HWE) reactions facilitated access to variety of densely substituted 1,3-butadienes attached with 1,3-diketone functionality at the terminal carbon. (C) 2015 Elsevier Ltd. All rights reserved.
RYABOV, B. V.;IONIN, B. I.;PETROV, A. A., ZH. OBSHCH. XIMII, 58,(1988) N 5, 969-983
作者:RYABOV, B. V.、IONIN, B. I.、PETROV, A. A.
DOI:——
日期:——
Nickel-Catalyzed Asymmetric Negishi Cross-Couplings of Secondary Allylic Chlorides with Alkylzincs
作者:Sunghee Son、Gregory C. Fu
DOI:10.1021/ja800103z
日期:2008.3.1
Complementing previous advances in allylation chemistry, an effective nickel/Pybox catalyst for regioselective asymmetric Negishi cross-couplings of racemic secondary allylic chlorides with readily available organozinc halides has been developed. The method has been applied in two key steps of a formal total synthesis of fluvirucinine A(1).
Ryabov, B. V.; Ionin, B. I.; Petrov, A. A., Journal of general chemistry of the USSR, 1988, vol. 58, # 5, p. 859 - 871